Add method override feature
Export MethodOverride in main module
Upgrade to heist 0.14

This is a breaking change and should bump our minor version in kind.
Loosen lens
Code clean up

This resolves some problematic dependencies and several
deprecation/linting warnings
Bump version to 0.11
Merge branch 'master' into poll-refactor

Conflicts:
	src/Snap/Extras/PollStatus.hs