When serializing into the xml the string property can be marked as not to be enclosed inside CDATA
Also fixed a bug where property metadata was not pushed onto the stack
Updated documentation
Added visitSimpleString function into the XmlSerializationVisitor. This method always serializes data into a text node.
DateTimeHandler supports that newly added feature.
added support for PHPCR
Merge pull request #184 from lsmith77/phpcr

[WIP] added support for PHPCR
Merge pull request #187 from mvrhov/noCdata

No CData
add xmlAttributeMap to serialized values
Merge pull request #204 from colinfrei/patch-1

Add xmlAttributeMap to serialized values
runs tests against hhvm
Allow overriding groups when descending into referenced objects.
Update reference documentation.
Fix error with missing MetadataStack in GroupsExclusionStrategy.

The error was triggered by Nelmio\ApiDocBundle, since it calls the
exclusion strategy without a MetadataStack present.