Throw an exception when pthread_key_create fails

Throw an exception when pthread_key_create fails

[Issue#] TWEB-427
[Feature] ThreadLocalVariable should not call Assert
when pthread_key_create fails
[Cause] Process gets SIGABORT when ThreadLocalVariable fails.
[Solution] Replace with exception, allow to catch it.

[Verification] Run iframes.wgt widget from wrt-extra repository.
WebProcess should not fail when counter in widget hits ~160.
Verification requires patch from plugins_common where this excepion is handled.

Change-Id: I7205afcaed091732f0233500e58d596fed1bdf4f