Simplified & improved apache proxy config

Previously there was an unnecessary redirect before & after sign-in to http.  This new configuration eliminates that leak, and is easier to read.
Changed port from 9292 (puma) to 8080 (unicorn)

Fixed port in the proxy backend address for unicorn on port 8080 instead of puma on port 9292.
Updated with suggestions from sag47

Made changes as per comments by @sag47

- Added ProxyPassReverse http://127.0.0.1:8080
Though I'm not sure what that's for.

- Simplified regex in rewriterule

- Put back in comments with links to external docs (nginx try)
Fixing rewriterule

The (.*) regex didn't work with gitlab 6.1 so I switched back to using REQUEST_URI.
Changed the http-https redirect rule

As per comments by @sag47 here:
https://github.com/gitlabhq/gitlabhq/issues/4997#issuecomment-25738169
Merge pull request #137 from semiosis/master

Simplify & improve apache proxy config for SSL