Fixed puma.rb environment setting

A small update of nginx example config to prevent users from issues while nginx not listen on localhost

Show only selected branch

A little change on wording for new-user email

included more details on searching for issues related to pull request

@options enable to keep params when switching ref.

Fixed a nginx configuration

update links to be relative paths and add CONTRIBUTING.md link

fixed fact about memory usage

fixed capitalization and added Google Analytics

Configure git global settings in installation docs

System calls to gitlab-shell were using unsanitized user input

Migrate notes.line_code format.

Since version 4.1, notes.line_code means:
  {SHA1 hash of file path}_{old line}_{new line}
but the older version means:
  {file index of the commit}_{old line}_{new line}

This rake task migrate the above differences.

Based on posting https://github.com/gitlabhq/gitlabhq/issues/3384#issuecomment-15457287 I was able to solved an issue here. Pointing out *:80 might could prevent others for struggeling here

Just a little change of wording for new-user email which looks better in my eyes.

Setting Git's global user.name and user.email are missing from
instructions, causing check.rake to fail at this step.
Signed-off-by: Axilleas Pipinellis <axilleas@archlinux.gr>

Update init.d script

The original init.d script uses a fixed username (e.g. git). Which is not flexible
when we using other user. So, I've updated it to use $APP_USER variable
instead and wrap it in a function to reduce repetitive codes.

Fix not using git.bin_path in config.

Add Gitlab::VersionInfo class to fix and simplify version check.