Rewrite build_url, use web_protocol for repo indicator.

Explicitly initialize custom port to make the logic obvious.

Should no longer freak out when omniauth settings aren't present in
gitlab.yml. People who aren't using it shouldn't even have to put a
'false' entry in their config for it (and probably wouldn't, after an
upgrade).

Merge branch 'master' into non-interactive-aws-install

Conflicts:
	doc/installation.md

Fix merge mess in installation.md

New config option: git_hooks_path

Closes #1237

of 'gitlab.yml'.

gitlabhq\config\initializers\1_settings.rb looks for
'gitolite_admin_uri' in the 'git' section of 'gitlab.yml'

Actually, that setting is in the 'git_host' section.
If not fixed, the 'gitolite_admin_uri' would always be equals to
'git@localhost:gitolite-admin', even if the administrator wants
to have another user than 'git' in charge of that repo.