In these particular instances we can just use HAML tags directly. This
can shave off some time spent loading issue pages, though this depends
on the amount of comments being displayed.

When viewing https://gitlab.com/gitlab-org/gitlab-ce/issues/2164 locally
these changes reduce loading time by about 400 ms in total.

By comparing objects in Ruby we can greatly improve the performance of
this method. In the worst case (should no data be eager loaded) this
will run the same amount of queries as before, in the best case (when
data _is_ eager loadeD) it requires no queries at all.

The added benchmark used to produce around 273 iterations per second.
With this commit this has been increased to almost 40 000 iterations per
second: a speedup of roughly 145 times.

Combined with eager loading Note associations this results in about 30
queries less when viewing a single issue, this in turn cuts down the
loading time by 30-40%.

This ensures that when viewing an issue each note already has the
associated project, project members, group and group members available.
Since this information is requres for every note this results in quite
the reduction of SQL queries being executed.

This can be used to measure the time (roughly) spent on a per line
basis. This can also be used to measure timings for views, for example
by adding the following to a URL:

   ?lineprof=app/views/projects/notes/_note

rack-lineprof is only enabled when:

1. The application runs in development mode
2. The used Ruby is MRI
3. The environment variable ENABLE_LINEPROF is set to a non-empty value

This can be used to track down where queries originate from, regardless
of whether they're caused by N+1 problems or not. This can be enabled by
setting the environment variable ENABLE_QUERY_TRACE to a non-empty value
(e.g. "true").

This can be used to resolve N+1 query problems. Bullet is disabled by
default and can be enabled by starting Rails with the environment
variable ENABLE_BULLET set to a non empty value (e.g. "true").

This removes the need for running a query to find the User object again
based on the supplied Email address.

This ensures we don't end up running N+1 queries for the objects in the
affected collections.

This removes the need for running an extra SQL query in these cases.

If the User object is already known before calling this method being
able to re-use said object can save us an extra SQL query.

Update uglifier to ~> 2.7.2

Fixes a security vulnerability:

- https://github.com/lautis/uglifier/pull/86
- https://github.com/mishoo/UglifyJS2/issues/751
- https://zyan.scripts.mit.edu/blog/backdooring-js/

See merge request !1590

Simplify the `issues_sentence` helper



See merge request !1598

Prevent a JS error in MergeRequestTabs

When `window.location.hash` is pointing to a note, e.g. `#note_1234`,
`scrollToElement` would throw an error because a selector such as
`.commits #note_1234` doesn't exist, so `offset()` returned `undefined`.

This error would prevent subsequent calls from running, which caused the
loading spinner to never be hidden.

Now we ensure the selector returns a valid element before trying to
scroll to it.

This is the proper fix for !1553.

See merge request !1597

Make Reply by email easier to configure

Builds on !1566.

Omnibus companion MR: gitlab-org/omnibus-gitlab!510 (cc @marin)

See merge request !1580

[ci skip]

Simplify code around (cross)-references

See merge request !1568

When `window.location.hash` is pointing to a note, e.g. `#note_1234`,
`scrollToElement` would throw an error because a selector such as
`.commits #note_1234` doesn't exist, so `offset()` returned `undefined`.

This error would prevent subsequent calls from running, which caused the
loading spinner to never be hidden.

Now we ensure the selector returns a valid element before trying to
scroll to it.

Show warning when build is pending and there are not runners

This change is based on: !1530.

This resolves #2967.



See merge request !1573

Add a few predefined variables to CI builds

This adds CI_BUILD_TAG, CI_BUILD_STAGE, CI_BUILD_NAME and CI_BUILD_TRIGGERED to build environment.

This change is based on: !1530 

See merge request !1572

Fix: Images cannot show when projects' path was changed

Fixes #1443

See merge request !1521

Revert "Improve invalidation of stored service password if the endpoint URL is changed"

This reverts commit b4639754.

See merge request !1595

This reverts commit b4639754.

Improve invalidation of stored service password if the endpoint URL is changed

A number of issues were found in !1490 and !1558 (triggered by support request 7395)

* It is not possible to set a new URL and a password at the same time (new password is ignored)
* An error occurs on the Service Templates admin pages (prop_updated? was referencing the service's project, which is not defined for templates)
* Passwords are reset on every save in Service Templates admin pages

This should fix these 3 issues by respectively:
* Differentiating a property that has been assigned a new value (regardless of the new value) and a property that has been assigned a new value that is different from the old one
* Providing an alternate implementation to detected updated properties, not relying on the service's project
* Filtering an empty password parameter passed to the Service Templates admin page like on the project service page

See merge request !1583

Slightly refactor runner status detection: moving it to Runner class
Signed-off-by: Kamil Trzcinski <ayufan@ayufan.eu>

Fix retry and cancel for build

This fixes some regressions introduced by Commit Status API

See merge request !1586