Advanced cache

Fixes #1993

* Build missing cache values in background job after each push
* Store commit_count in project table. Refresh in background job
* moved repository size calculation in background job


## Advantages

Every time push is triggered - we build cache for project even without user visiting project page. 
That means first visit is as fast as others now. This is especially good for active projects where people have some requests fast because of cache and some slow - because cache was build in their request. 

Between cache expired and cache built we we had gap when Linux repo can give 502 error because calculation commits count takes 30 seconds or even more. 
Using value from database fix this problem. Before cache is updated you see old value from database. After - you see new one. 

Basically this merge request is super win to GitLab. We don't do some heavy operations in user request but instead in background job. 

## Temporary problem

After this migration all projects will have `0` commits in database. It fill be replaced with real value on next push. I did not add recalculation to migration because it will last forever on big instances.  Can be fixed by adding rake task which will go in background on live instance without downtime

See merge request !986

Time ago fix for compare page



See merge request !1905

7-13 stable: changelog update



See merge request !1901

This reverts commit 8a01a122.

fixed notifications title

I fixed the title and link to this document because I believe that it's more clear and easier to find if it has "emails" in the name.


See merge request !1897

Fix path to move_drop_indexes.ed

Small documentation fix.

See merge request !1900

Add nice scroll for sidebar
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

See merge request !978

Hide scrollbar from sidebar when external mouse is connected to OSX

See merge request !977

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

create update guides for 7.13



See merge request !1899

Move coverage-related setup back to spec_helper

These tools must be loaded before our regular Rails environment.

Partially reverts 57830201

See merge request !976

Add 'ed' step to mysql-to-postgres procedure

This change brings the documentation in this repo up to date with that in https://github.com/gitlabhq/mysql-postgresql-converter .

See merge request !1896

Fix mentions not being created upon issue/merge request update

New cross-references weren't being added when they were made in an issue or merge request update.

This happened because the relevant `UpdateService`s were making the `notice_added_references` call
after the model had already been updated and saved, so the `changes` attribute was empty and no
cross-references were made at all.

This fixes the bug and adds a bit of testing and a bit of refactoring.

Closes #1773

See merge request !974

Allow user to specify content he wants to see on project page

Improvement to !938. Since a lot of people complain on fact they don't like to see README.
Especially since we already have a switcher for dashboard - it kind of acceptable to select behaviour.

User can specify which content he/she wants to see:

![Screenshot_2015-07-13_18.24.31](https://gitlab.com/gitlab-org/gitlab-ce/uploads/d237474e8f52df4a62ba7e951fa28bd8/Screenshot_2015-07-13_18.24.31.png)

![Screenshot_2015-07-13_18.24.36](https://gitlab.com/gitlab-org/gitlab-ce/uploads/473b0e2a94b3de16d048b8332b539816/Screenshot_2015-07-13_18.24.36.png)

cc @JobV @jacobvosmaer @marin @sytses

See merge request !970

These tools must be loaded before our regular Rails environment.

It now accounts for models that have changed but have already been
persisted, such as when called from an UpdateService.

Closes #1773

Replaced icon for project page dropdown button

Improve for !971

![Screenshot_2015-07-13_23.37.01](https://gitlab.com/gitlab-org/gitlab-ce/uploads/2b168c6f8a07f33cab4ca8f735646f8a/Screenshot_2015-07-13_23.37.01.png)

See merge request !973

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Use password field defaults for services

Previously we masked the password field manually. After the refactor that services page received we can use `password_field` default masking.

Fixes internal https://dev.gitlab.org/gitlab/gitlab-ee/issues/314

See merge request !969

Add dropdown to quickly create issue or branch from project page

because just 'new issue' link is not valid for all users. A lot of people use external issue tracker. So I grouped several links under one button

![Screenshot_2015-07-13_18.40.43](https://gitlab.com/gitlab-org/gitlab-ce/uploads/9db7394c16d1a8718c8a6a15fd2c98cc/Screenshot_2015-07-13_18.40.43.png)

![Screenshot_2015-07-13_18.40.41](https://gitlab.com/gitlab-org/gitlab-ce/uploads/d880532bb15370bb3f8e76bd06b411ad/Screenshot_2015-07-13_18.40.41.png)

cc @JobV @marin @jacobvosmaer @sytses

See merge request !971

Scroll sidebar

On small screens content of sidebar does not fit. This merge request makes sidebar scrollable which makes it usable for tablets and small laptops.

This merge request has no screenshot because it brings no visual change. Its about action.

cc @darby @JobV

See merge request !972

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Introduced in
https://github.com/gitlabhq/mysql-postgresql-converter/commit/b2d1599706f532e1bac836243f25e005c816ef14