Issue 7 Provide ability to determine file dependencies
Collections of dependencies are not sets. Also, a dependency must be constructed with it source references. So a
dependency is read-only now. Also, set up equals and hashcode methods for dependency. Also a bit of stuff
relating to uploading of dependencies. The source references property in the CND is now mandatory.
Update XsdDependencyProcessor.java

Added session save.
Merge pull request #102 from elvisisking/dep-set

Issue 7 Provide ability to determine file dependencies