Sampling data at a fixed interval means we can potentially miss data
from events occurring between sampling intervals. For example, say we
sample data every 15 seconds but Unicorn workers get killed after 10
seconds. In this particular case it's possible to miss interesting data
as the sampler will never get to actually submitting data.

To work around this (at least for the most part) the sampling interval
is randomized as following:

1. Take the user specified sampling interval (15 seconds by default)
2. Divide it by 2 (referred to as "half" below)
3. Generate a range (using a step of 0.1) from -"half" to "half"
4. Every time the sampler goes to sleep we'll grab the user provided
   interval and add a randomly chosen "adjustment" to it while making
   sure we don't pick the same value twice in a row.

For a specified timeout of 15 this means the actual intervals can be
anywhere between 7.5 and 22.5, but never can the same interval be used
twice in a row.

The rationale behind this change is that on dev.gitlab.org I'm sometimes
seeing certain Gitlab::Git/Rugged objects being retained, but only for a
few minutes every 24 hours. Knowing the code of Gitlab and how much
memory it uses/leaks I suspect we're missing data due to workers getting
terminated before the sampler can write its data to InfluxDB.

See merge request !2392

added make command to docs

The gitlab-workhose update docs are missing a make command

See merge request !2281

See merge request !2389

Where a vew is called from doesn't matter as much. We already know what
action they belong to and this is more than enough information. By
removing the file/line number from the list of tags we should also be
able to reduce the number of series stored in InfluxDB.

This gives a very rough estimate of how much memory is allocated during
a transaction. This only works reliably when using a single-threaded
application server and a Ruby implementation with a GIL as otherwise
memory allocated by other threads might skew the statistics. Sadly
there's no way around this as Ruby doesn't provide a reliable way of
gathering accurate object sizes upon allocation on a per-thread basis.

Add user's last used IP addresses to admin page

This would help admins figure out from where spam is originating.

Screenshot:

![image](/uploads/984005a3a35b7004bd0a363081eb53ba/image.png)


See merge request !2381

Improve button styles

I noticed a couple of buttons don't match the newer styles.

## Issue edit note form

### Current (cancel button is big)

![Screen_Shot_2016-01-08_at_2.18.29_PM](/uploads/c7928e6644e886090f55cb61076c9e89/Screen_Shot_2016-01-08_at_2.18.29_PM.png)

### Now

![Screen_Shot_2016-01-08_at_2.18.22_PM](/uploads/d15c3c458a08ce5a59c367c7fb379c31/Screen_Shot_2016-01-08_at_2.18.22_PM.png)

## Merge request code discussion

### Current

![Screen_Shot_2016-01-08_at_2.21.37_PM](/uploads/b970ff3e5d9ef5e62f83bb56d5505f8d/Screen_Shot_2016-01-08_at_2.21.37_PM.png)

### Now (Also changed to `btn-save` class which changes to green. This matches everything else)

![Screen_Shot_2016-01-08_at_2.22.01_PM](/uploads/ed520de72177de92efe21d236bb04d24/Screen_Shot_2016-01-08_at_2.22.01_PM.png)

cc/ @jschatz1 @skyruler @creamzy 

See merge request !2350

See merge request !2385

I forgot to add these in the respective MRs.

[ci skip]

This would help admins figure out from where spam is originating.

Bump fog to 1.36.0

Updates AWS regions and fixes a number of bugs. Tested a GitLab AWS backup without any issues.

Closes #4231

See merge request !2373

adds hover titles to merge request and issue pages

Fixes #5899

See merge request !2375

changes bolded on active for dropdowns, sitewide.

Fixes #6056 <br/>
 **Note:** this change applies to all dropdowns. Currently all dropdowns using bootstrap's dropdown.js apply a bold and larger font for an active state.

See merge request !2377

Add title attribute to Emojis in award picker



See merge request !2378

Remove the `:coffee` and `:coffeescript` Haml filters

See https://git.io/vztMu and http://stackoverflow.com/a/17571242/223897

See merge request !2380

See https://git.io/vztMu and http://stackoverflow.com/a/17571242/223897

[ci skip] Fixed minor typo in docker documentation

This change is self-explanatory.

See merge request !2374

Call clearInterval for the currentTimer if one exists

Prevents a double-click from causing the logo to sweep forever after a
load completes.

See merge request !2379

Prevents a double-click from causing the logo to sweep forever after a
load completes.

[ci skip]

Allow subsequent validations in CI Linter

Closes #5851

See merge request !2368

Generate builds when creating tag using web interface

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/4296

See merge request !2366

Use gitlab-workhorse 0.5.3

See merge request !2367

Optimize LDAP and add a search timeout

Related to #4282 

This merge request arranges some things in `access.rb` to facilitate some optimizations in EE (to come later). It also adds a 10 second timeout to all LDAP searches so the entire worker is not blocked if some query doesn't return in a reasonable amount of time. This timeout is configurable per LDAP server.

See merge request !2267

See merge request !2370

Closes #4231

Without this it's impossible to find out what methods/views/queries are
executed by a certain controller or Sidekiq worker. While this will
increase the total number of series it should stay within reasonable
limits due to the amount of "actions" being small enough.

Add versions to omniauth_crowd and omniauth-azure-oauth2

Also sorts them alphabetically, because OCD.

See merge request !2364

Improve performance of getting issues on group level

For testing I used the URL http://localhost:3000/groups/gitlab-org/issues?milestone_title=8.1. Prior to these changes said URL would take about 10-12 seconds to load. By applying these changes the loading time has been reduced to roughly 2-3 seconds. 

There's still some stuff going on in some views that I have to look at, resolving those changes might reduce the loading time a bit more. I also still have to check if I didn't break too many tests.

Fixes: gitlab-org/gitlab-ce#3707 gitlab-org/gitlab-ce#4071 

See merge request !2318

Use WOFF versions of SourceSansPro

See https://gitlab.com/gitlab-org/gitlab-ce/issues/6023

See merge request !2357

Refactor ZenMode

- No longer depends on the "hidden checkbox".
- No longer depends on manually storing/restoring the scroll position.
  Instead, we take advantage of jquery.scrollTo.
- Event-based.
- Simplifies the state-based styling.

See merge request !2354

use JavaScript instead of CoffeeScript in Views for master