Few ongoing improvements and bugfixes

Hey guys, have a look at this. Once merged we can release 1.0.7.

Summary:

• Some admin actions for Shifts and Studies
• Some display issues (missing Id's and sorting studies)
• Tables (studies and assets) fixes sorting/columns
• New pages:
  • team inconsistencies
  • the creation of new revisions at the import
  • team backend merge/delete shifts