Responsive sidebar fixes

This fixes two major issues with the responsive sidebar

1. Overlapping content by the label:
The label and sidebar is now always on the right side of the screen. This makes it always easy to find (better UX) and prevents it from overlapping most content. Additionally, on xs screens, instead of the side-attached label, for some pages it will show an extra button in the head instead of a buttons that overlaps.

2. Pop up of sidebar on changing pages.

Show file mode changes on commit page

## Before:

![Screenshot 2014-06-14 22.55.18](https://dev.gitlab.org/uploads/dzaporozhets/gitlabhq/3f89dfa841/Screenshot_2014-06-14_22.55.18.png)

## After:

![Screenshot 2014-06-14 22.54.11](https://dev.gitlab.org/uploads/dzaporozhets/gitlabhq/5e7550d595/Screenshot_2014-06-14_22.54.11.png)

move all sidebars to one side for improved UX; add button in head of projects/issues and milestones instead of tab on side of screen to prevent overlapping of content

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>

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>

Responsive sidebar

Puts the sidebar on the dashboard in a off-screen sidebar that can be called by pressing a button with a fixed position.

Any sidebar with the .responsive-sidebar class will follow this behavior. Button must be added manually.

Cleanup help

Remove a lot of unused help files.
Apply `wiki` css to help content

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

UI/UX improvements

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

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

Conflicts:
	CHANGELOG

Issues sentence helper

This will make merging CE into EE later easier.

More secure api

Dont expose user email via API. Fixes #1314

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>

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

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

Git 2 docs

Related to #1318

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

To prevent leaking of users info we reduce amount of user information
retrieved via API for normal users.

What user can get via API:

* if not admin: only id, state, name, username and avatar_url
* if admin: all user information
* about himself: all informaion
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

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

Fix 502 error on new merge request page

When diff is huge we try to render it that cause 502 error often.
After this patch we apply soft limits to diffs. So if diff is huge - we doing show it

Fixes #1323

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

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

Conflicts:
	CHANGELOG