Per class read only
Merge remote-tracking branch 'origin/master' into read-only-class
Xml lack docs
Added test files
Fixed issue on read only attrubute in XML mappgin
A property can be marked as non-read only
Code style
xml documnentation
Merge pull request #227 from goetas/read-only-class

Read only class
updates version
Testing collections of polymorphic objects
Fix in GraphNavigator for serialization of polymorphic objects