ni_nitdoc: moved JS facilities to Nitdoc.UI module

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
ni_nitdoc: moved JS quick search to Nitdoc.QuickSearch module

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
ni_nitdoc: moved JS GitHub to Nitdoc.GitHub module

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
ni_nitdoc: simplified github option

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
ni_nitdoc: uniformized graphic style

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
Merge remote-tracking branch 'alexandre/mmnitdoc'

Revised version of the Nitdoc GitHub plugin.

Easier configuration, only one option: --github-origin user:repo:branch
to set the upstream branch that will receive pull requests.

Also made some graphical improuvments.