Fix git repo and update mweb_events
Allow the event module to be enabled/disabled dynamically

Added a flag to Site to enable or disable the module. If disabled, disables
everything, including its routes.

The gem will still always be installed and db tables will still always be
created.

refs #1115
Making page titles better looking and some updates on events

- Updated MwebEvents, now with better logo images
- Updated all default images for events, spaces and users, with a bit more
  transparency
- Made page titles look better in general. Some now also have a subtitle.
- Moved all locales related to MwebEvents to their own file.

refs #1115
Better css for mweb_events/events/show

refs #1115