docs: installation on Ubuntu

* tested the installation process on Ubuntu Saucy (13.10)

* using 100% more pygments.

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>
docs: cleanup of git-workflow

* removing remaining Trac-ish formatting

* removing Trac related features (like closes)i

* added the missing pictures

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>
search: fix initial request missing stylsheets.

* Putting the stylesheets into the header block.
  The css block occurs after css bundle so they don't make it the
  first time. As everything goes through Flask Assets, using the
  header block for js and css seems the way to go.

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>