webos-image: libpbnjson=21

:Release Notes:
Fixed JSON schema validation in multithreaded environment. Added JSON
schema validation doxygen documentation. Slightly improved JSON schema
validation performance.

:Detailed Notes:
libpbnjson: submissions/21..submissions/22
64be9d7 Fix JSON schema validation in multithreaded environment
885507f Improve memory allocations during validation against JSON schema
15f43bc Add performance measurements tests for schema validation
bd41dc0 Modify *_put functions to always take ownership
d319bbf Document schema validation

:Testing Performed:
miniBAT

:QA Notes:

:Issues Addressed:
[GF-38364] pbnjson: Document schema validation
[GF-9986]  libpbnjson: Refactor jobject_put and jarray_put() to take
           ownership even in case of error
[GF-38338] pbnjson: Measure and tune schema validation performance
[GF-42809] pbnjson: Fix reference counting of generic_validator (and
           alike) in multithreaded environment
[GF-43271] CCC: libpbnjson=21

Open-webOS-DCO-1.0-Signed-off-by: Mykola Kryvonos <mykola.kryvonos@lge.com>

Change-Id: I70b52e59f561ded86e6b9d91a3c62fcc3439cef0
Reviewed-on: https://g2g.palm.com/3708
Reviewed-by: Build Verification
Reviewed-by: Susan Montooth <susan.montooth@lge.com>
Tested-by: Susan Montooth <susan.montooth@lge.com>