reproducer for JERSEY-2091

Change-Id: I360e7db0f8b00d510d926bc62c95fad76b0e522c
JERSEY-2086: NPE when adding item for sse-item-store-webapp (WLS, Firefox)

- Added check (although list in current example accept null).

Change-Id: Ie8a5dc3578af93ace2b0a9c216813301f5ccc8fd
Merge "JERSEY-2086: NPE when adding item for sse-item-store-webapp (WLS, Firefox)"
Merge "reproducer for JERSEY-2091"