Add's another cache that has out-preformed the MultiTriggerCache and Summing cache in benchmarks
Swap the default for the async cache to the YAC
Made def abstract
add missing needed Algebird upgrade that fixes some sparse monoid action. Also simplified the yet another cache to have less synchronization concerns
Rename new cache over to a more sensible descriptive name
Review comments
Merge branch 'develop' of github.com:twitter/summingbird into YetAnotherCache

Conflicts:
	project/Build.scala
Updated Stats supplier
Add more constructors
Add more metrics
Realise lazy stores on init
Merge branch 'release/0.4.0'
Merge branch 'release/0.4.1'
replace monoid reference by semigroup
Merge branch 'develop' into monoid_to_semigroup
add doc
typo
Merge pull request #487 from julienledem/monoid_to_semigroup

Monoid to semigroup
Add some option documentation
Incorporate Ian's comments