webos-image: libpbnjson=20,v2.1.0

:Release Notes:
submissions/19..submissions/20:
249595d Redesign JSON validation against schema
acef3b1 Update to YAJL-2.0

:Detailed Notes:
Validation against JSON schema has been completely redesigned: it
precompiles a schema into a recurrent structure of validators aware of
particular parts of target JSON. This allows to check JSON instances as
they are parsed without additional memory allocations or other expensive
operations. This improves performance of the parser by the factor of
two.

Additionally, the library has been upgraded to support YAJL-2 (while
retaining YAJL-1 support).

:Testing Performed:
Unit tests passed.
Unit tests with memory checker passed.
Smoke test on a real device passed.
MiniBAT results attached to the CCC in JIRA.

:QA Notes:

:Issues Addressed:
[GF-8140]  Upgrade libpbnjson to YAJL-2
[GF-13496] pbnjson: Redesign validation against schema
[GF-35713] Make new validator compatible with the old one
[GF-35717] Fix small issues after validator integration
[GF-37961] CCC: libpbnjson=20,v2.1.0

Open-webOS-DCO-1.0-Signed-off-by: Anatolii Sakhnik <anatolii.sakhnik@lge.com>
Change-Id: Iec60e3c0e12c105dd76c5c5c848c795668ee9b00
Reviewed-on: https://g2g.palm.com/3403
Reviewed-by: Herb Kuta <herb.kuta@lge.com>
Tested-by: Herb Kuta <herb.kuta@lge.com>
Reviewed-by: Build Verification
Reviewed-by: Susan Montooth <susan.montooth@lge.com>