[FIX] utf-8 encoding of resources PDF conversion

closes #1371
[MIN] i18n
[MIN] Removed unnecesary temp variable
[FIX] RoomBooking: Blockings bars

* closes #1289
* They span a whole day
* They are rendered in the furthermost layer
* They cannot be clicked
[FIX] RoomBooking: Reservation on blocked rooms

* Candidate bars: ajax click to check if user can override blocking
[MIN] PEP8
[FIX] Warning message for pre-bookings

- closes #1338
- warning toggles with success (already contains similar message)
- deleted extra css and instead utilized of messageboxes partial
- vars -> wvars
[ADD] backbone, modenizr and polyfill
[FTR] WYSIWYG Registration form

   * WYSIWYG registration form
   * Page rendered on client side
   * HTML5 Validation
   * Position changes can be done with Drag-and-drop
   * Single page for editing of the registration form
   * Radio group buttons can be now ordered by the user
[DEL] previous version of the registration form
[IMP] Better field chooser
[FIX] After flask rebase fixes
[IMP] Update webshim, backbone, jquery-migrate

- Added backbone to ext_modules
- Added webshim to ext_modules
[REF] Move RegForm CSS to SASS folder

- PEP8
[FIX] Several fixes

- Backbone views initialization
- New toolbar
[REF] Moved registration fossils to core
[FIX] RegForm display rendering process
[FIX] Several fixes

- Backbone views initialization
- New toolbar
[IMP] RegForm: CSS cleanup
[IMP] RegForm: HTML cleanup

Removed unnecessary <table> elements