Modified _validateJSON to not give an error if jsonschema module is not found.
Modified check for pubsub version - in 3.0 this was changed from
PUBSUB_VERSION to VERSION_API
converted -strip these files because of an sRGB warning.
Added try/except around import of jsonschema
Merge remote-tracking branch 'origin/master'
Minor fix
1. Fixed context-path to use the value from lisp rather than the cached value
2. Added a pvs-server command