Merge branch '1.7' of github.com:evert/SabreDAV into 1.7

Conflicts:
	ChangeLog
Merge branch '1.8' of github.com:evert/SabreDAV into 1.8

Conflicts:
	ChangeLog
Merge branch '1.7' into 1.8

Conflicts:
	ChangeLog
Merge branch '1.8'

Conflicts:
	ChangeLog
Added the $propertyMap argument to unserialize() methods.
Refactored multi-status parsing into their own properties.
Added an additional check for xml bodies.
English
Added 'naturalselection' to composer bin's.
Oops!
CalDAV SharingPlugin plays nicer with others.
Merge branch '1.7' into 1.8

Conflicts:
	lib/Sabre/CalDAV/SharingPlugin.php
	lib/Sabre/CalDAV/Version.php
	lib/Sabre/DAVACL/Plugin.php
Merge branch '1.8'

Conflicts:
	lib/Sabre/CalDAV/Version.php
Typo in migration script. Fixes #298
Merge branch '1.8'
- using the DOM to build the request for prop find & proppatch
- using serialize-functions of \Sabre\DAV\Property to support complex properties in proppatch
Merge branch 'master' of https://github.com/evert/SabreDAV
using createElementNS instead of setAttribute
fixed unit tests
using relative class name