* honour calendar-proxy-read/write-for property
* ignore errors when quering member groups for home sets
* remove home sets and collections from the service database not only on 404, but 403, 404 and 410
* fix crash bug when <displayname> was defined, but empty
* new icons with 3D effect as required in Android Iconography Guide
* target SDK version updated to 20
* replaced UI directions left/right by start/end for RTL support
* Show "unnamed calendar"/"unnamed address book" instead of "null" in "Select collections" fragment
* "Add account" button now directly adds DAVdroid account
* .svgz for "How DAVdroid interacts with other components" added to doc
* relevant RFCs go into the doc/ directory for reference purposes
* read-only calendar collections are set as read-only in Android
* HTTP exception refactoring to mark 4xx HTTP errors as hard sync errors (numAuthExcetions/numParseExceptions) for Android sync manager
* query current-user-privilege-set for resources, detect read-only resources
* show read-only resources as read-only in SelectCollectionsFragment
* minor refactoring (DavProp.*)