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.
Display correct paths in markdown for reference style links.
Include a note for people that think the headers are wrong.
Markdown helper spec for reference style relative links.
Test if the views behave correctly with reference style relative links.
Update last sha of the commit in the test seed repository.
Use the correct paths.
Merge branch 'master' into reference_relative_links

Conflicts:
	spec/models/project_spec.rb
Allow developers to mange issue tracker

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Improve authorization for new/edit blob pages

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
 Merge branch 'improve/developer_permissions' into 'master'

Permissions: Developer can manage issue tracker now
 Merge branch 'reference_relative_links' into 'master'

Reference style links with relative links in markdown

#996

```
Adds relative links support to reference style links, eg:

[GitLab API doc directory][GitLab API directory listing]

[Maintenance][Maintenance rake task]

\[GitLab API directory listing]: doc/api/
\[Maintenance rake task]: doc/raketasks/maintenance.md
```
Version to 6.6.0.pre

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
 Merge branch 'database-confusion' into 'master'

Database Confusion

To prevent https://twitter.com/TechIsCool/status/426133762032676865
Merge pull request #5907 from boomshadow/patch-1

Update installation.md with new git version