Merge pull request #324 from iskiselev/master

Added JSStubOnly attribute for simplification creation of class sutbs.
Update README.md
Support of multiple serialization assemblies.
Fix #328. Only System.Xml.XmlConvert declared.
Changed Assembly .toString() with Assembly.FullName.
Merge pull request #334 from iskiselev/XmlDeserializationMultiAssembly

Support of multiple serialization assemblies.
JSIL for HCS intial change.