TODO

* mobile support: better edit dialog
* add doubletap event on touch for edit
* make long tap delay longer
* profile page
  * link to change password
  * display API key
  * regenerate API key
* reset drag position on window resize (eg: rotate)
* allow user to select alternate bg colour for an activity
* fix next/previous when cursor is 'in space'
* initialise cursor to current time if today is in the target week
* date picker to select week
* pop-up help for key-bindings
* key bindings for increase/decrease activity duration
* undo ?
* handle public holidays
* websockets channel to advise of updates from other clients

Other stuff:
Screen size as reported by S3 phone: 360 x 567
https://github.com/dotmaster/Touchable-jQuery-Plugin
https://github.com/mmikowski/jquery.event.ue