An architectural overview of GitLab

This is to help new admins of GitLab understand what components
are involved in making GitLab work.
update links for gitlab.com
Clarifying web frontend direct file access

Rewrite how Apache/nginx interacts with precompiled assets.
updating structure doc
adding ref from structure to architecture
Remove unnecessary text shadow

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Highlight code search results
Use 100% width for note edit form
Remove shade for reopen button
Fix protected branches page UI
Fix no-highlight code blocks for dark themes
 Merge branch 'ui_fixes' into 'master'

UI Fixes
Merge pull request #6185 from sag47/doc/archy_overview

An architectural overview of GitLab
Replace pygments with hljs for system hooks help page

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Get rid of pygments.rb dependency

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Remove python from installation docs

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

Remove Pygments.rb
Use linguist from rubygems

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Fix shifting line numbers.
 Merge branch 'fix/line-numbers' into 'master'

Fix shifting line numbers.

When there are 1000 lines or more in a file, the link icon causes the numbers to shift down a line when you hover over the line number. This fixes that issue by setting a `nowrap` option for the line number anchor tag.

I also removed the fixed width of 60px for the `line-numbers` div as this causes issues for longer line numbers. I used `visibility: hidden` instead of `display: none` to ensure that the space for the link icon is taken into account. This way auto sizing the div does not cause any problems.

You can see the current behavior by looking at the following:

https://gitlab.com/gitlab-org/gitlab-ce/blob/master/vendor/assets/javascripts/ace-src-noconflict/mode-java.js