Use sinon sandbox to avoid extra restore() calls
Test cleanup and minor improvements
All power to jshint
Improve tests for 'warn' and 'none' log levels
Add loglevel tests for all levels
Fix loglevel precedence
Fix accidental global variable while I'm here
Merge pull request #31 from fmtvp/TVPJSFRMWK-798

Fix log level bug - 'log' messages should be written at 'info' level