1.2.4

Francis Galiegue (11):
      Bump version number
      Introduce SchemaKey
      BaseSchemaTree: reorganize instance variables
      SchemaKey: add static factory methods
      BaseSchemaTree: use a SchemaKey
      BaseSchemaTree: implement equals()/hashCode()
      Dereferencing: use new SchemaKey constructors
      AnonymousSchemaKey: fix brown paper bag logic bug in equals()...
      More documentation; modify tests to use the new API
      Remove deprecated API usage in tests
      Remove {project,settings}.gradle