Add verification for CyberSource2 implementation.
Clean up shopping cart processor API.
Fix UUID JSON serialization bug in CyberSource2 implementation.
Update test suite to use new CyberSource2 implementation.
Fix i18n messages in CyberSource2
Enable CyberSource2 implementation by default.

Conflicts:
	lms/envs/dev.py
edx-west cybersource changes
Merge pull request #120

from Stanford-Online:jbau/cybersource2
into Stanford-Online:master