Fix for Bug 394.

Fixed bug in grammar when handling nested unknown nodes.
Fixed parsing nested unknown nodes in YangParserListenerImpl.
Added test.

Change-Id: I9c336a30d9f0a955a9914968a9eaad17154398e5
Signed-off-by: Martin Vitez <mvitez@cisco.com>
Fix for Bug 364.

Fixed parsing of config statement:

Modified DataSchemaNodeBuilder:
- changed isConfiguration return type from Boolean to boolean
- changed setConfiguration parameter return type from Boolean to boolean
Updated YangParserListenerImpl and DataSchemaNodeBuilder implementations.
Fixed bug in ContainerSchemaNodeBuilder.build() method.
Fixed bug in GroupingBuilderImpl.

Signed-off-by: Martin Vitez <mvitez@cisco.com>
Merge changes Iaac9f7e2,I9c336a30

* changes:
  Fix for Bug 364.
  Fix for Bug 394.