Refactoring the property-updating system. Work in progress.
The new proppatch object is now fully tested.
All the DAV tests run again.
ACL refactoring.
Refactored Cal- and CardDAV
Merge remote-tracking branch 'origin/master' into property-refactor
Lots of formatting/docblock changes.

thnx @staabm
To more license tags.
Merge pull request #429 from fruux/property-refactor

Property refactor