This commit has some improvements for Analytics Systemless Test
- Increase stat coverage for UUID and SUM cases
- Support cleaner shutdown of tests when Ctrl-C interrupts the test
- python generator fixture should shut down the sandesh connection on cleanup
- mockredis and mockcassandra can tollerate tmp files already existing : delete tmp files before launch, and use username as part of tmp filename.
Merge pull request #471 from Juniper/anishm_sysimp

This commit has some improvements for Analytics Systemless Test