Migrating these out from summingbird to more general location
Add tests, fix some bugs. Function name/style refactoring
Remove some debugging code
Hll optimizations
Optimize the storage backend used in sketch map
Merge pull request #299 from twitter/feature/HLL_optimization

Optimize HLL sumOption
Remove unused variable
Merge pull request #301 from twitter/sketchmap_opti

Optimize the storage backend used in sketch map
Merge pull request #296 from twitter/feature/migrateAsyncSummersFromSB

Feature/migrate async summers from sb