Frontend access rights through corporation titles

[henning-gerhardt]

precondition: #31 needed:

• [x] corporation key with right access mask
• [x] character key with access to character sheet

to do:

• create, read, update, delete:
  • [x] corporation titles
  • [x] character titles
• [x] defining which corporation titles belong to which frontend user group

[henning-gerhardt]

Implemented