Make assertions a little more expressive
Change Activity API: registeredMembers is now a function, not a direct property access
Extract registeredMembers into Resource object (rather mechanically for the first step)
Fix loading of registeredMembers from Resource
Move member add/remove from Activity to Resource
Use dictionary to store Resources instead of array (allows acces by name)
Make modes of Activity construction explicit
Change values of exisiting activity object instead of recreating it

Fixes bug that we lose registered memebers when editing the activity.
Note areas for improvement
Merge pull request #448 from wosc/limited-activities

Introduce Resources for Activities
update for init script to make editable groups
groups edit now with co-ordinates and label
made popovers wider - slight code cleanup
wtf - see comment in code
Revert "wtf - see comment in code"

This reverts commit a0299a2b625f5873cd3119cedfa01ec223a77383.
jQuery is not always happy with easy iterations :(
Merge pull request #449 from leider/master

made popovers wider - slight code cleanup