Add timeShift natively

[shanson7]

Describe your changes
Implement timeShift natively

Testing performed
test files added
A/B testing against graphite using https://github.com/shanson7/mtcmptest

Additional context
There are a few scenarios that are a little strange:

1. resetToEnd does not seem to work when data is retrieved from MT (whether by graphite or natively). I think it's due to padding the data to the requested end.
2. alignToDST is hard to test on UTC servers :) It uses the server timezone (which I think is misleading to users) and that may be different in the Mt deploy than the graphite deploy

[robert-milan]

I agree, we can leave support out for resetEnd. Other than that it looks good. I tested it locally. Just need to fix the conflicts and I think it is ready for merge.