* translated part of the timetracker js code in coffeescript
* fixed error msg on attempting to delete a tracking with attached bookings
* extracted validations in an extra coffee class
Merge remote-tracking branch 'origin/master'
* changed timetracker validation using the new formvalidator class
* renamed validations file in validators
* extracted update methods in own class
* removed validation from onchange for add_booking_form
* made form validation unobstrusive
* fixed validation not getting initialized
* made field updater unobtrusive
Merge remote-tracking branch 'origin/master'