Room Booking - improvements in booking workflow

[pferreir]

Suggestions from CERN's GTPE:

• Add an option that allows owners to define whether a room can be booked in a recurrent way or not.
• Add greater control over who can (pre-)book
  • Imagine a list of roles (owner, management e-group, booking e-group, everyone else...) and a single-choice stating whether they can book, pre-book or do nothing.

These are just ideas on how to implement it. The role of Gesloc should be properly evaluated.