Bug 2271 - NPE during generation of java binding for case list-grouping-choice

The SchemaContextUtil class does not find some types of schema elements nested
in other elements (e.g. groupings in groupings - Bug 2117, groupings in lists,
groupings in Rpcs, groupings in rpc outputs and inputs, groupings in
notifications etc...). Therefore complete rework of findNodeInModule and
related methods has been performed. This version of patch set (i.e. 5) works
also with yang modules containing siblings with the same name.

Change-Id: Ia5f9d437c05ace6d94999eac17308a756c439f82
Signed-off-by: pkajsa <pkajsa@cisco.com>
Merge "Bug 2271 - NPE during generation of java binding for case list-grouping-choice"