Reduce image size.

Checking the site with the PageSpeed extension, one of the reports was
in reducing image size.  This reduced the number of bytes by 67%.

It was done with optipng -o7 -fix *.png in the app/assets/images dir.

References:
  optipng: http://optipng.sourceforge.net/
  PageSpeed extension: https://developers.google.com/speed/docs/insights/using_chrome
Update installation.md

Updated the version of Git used in the section for compiling Git from source.

Also, changed the verbiage used in the section "Initialize Database and Activate Advanced Features". It previously said to type 'yes' to install the database.
Merge branch 'master' into logo-white-compress

Conflicts:
	app/assets/images/logo-black.png
	app/assets/images/logo-white.png
Another optipng run over png's.

Ran optipng -o7 -fix over all png files. This should make pages load a
tiny bit faster (you can test this with the pagespeed tool on firefox or
chrome).

It might be an idea to add *lossless* image compression optimization
runs to the release process.
Also optimise gifs with gifsicle.

These are the same gif files just after running
gifsicle -b --optimize **/*.gif
Removed hash from "<user> #pushed to branch..." Hipchat notification
Create separate table to store Merge request commits/diffs

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Improve db schema for merge request diffs

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
MergeRequestDiff model responsoible for storing commits/diff info

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Remove commits/diff store login from MergeRequest model

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Render MR diff correctly

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Set mr_diff state to collected if diff is ok

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Improve commit render performnace for MR show page

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Display correct paths in markdown for reference style links.
Merge branch 'master' of dev.gitlab.org:gitlab/gitlabhq into improve/mr_diff
Always create merge_request_diff if MR created

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Make changes to tests

* project_with_code -> project
* project -> ermpty_project

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Correct section number for 'Check application status'
Fix api merge request specs

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Enhance responsive UI for the login screen.