Fix assistance option on reservation modification

Close #1698
Revert "Fix assistance option on reservation modification"

This reverts commit 9f03d18beaf8a259e2c878c25ef6def9ae28a78e.
Retain TZ when editing contribution date/time
Add files for style FAST
Prevent goto next page when pressing enter in RB

 - prevent the default behavior of submitting the form when pressing enter in
   the room booking capacity filter which leads to going to the next page
 - the capcity filter now behaves like the rooms filter and auto-updates live
 - fix #1687
Merge branch 'v1.9'