Performance: Leverage jinja2's Environment to cache compiled Templates.
Merge remote-tracking branch 'origin/master' into ImproveTemplatePerformance

Conflicts:
	moto/s3/responses.py
Performance: Leverage jinja2's Environment to cache compiled Templates. (fixed merge)
Merge pull request #281 from DreadPirateShawn/ImproveTemplatePerformance

Performance: Leverage jinja2's Environment to cache compiled Templates.