BatchedReadableStore
remove batchFn and add implicit FutureCollector
Add MergeableJMapLongStore and accompanying tests

This class is very handy for testing code that interacts with a
MergeableStore[K, Long] instance.
Refactor for more idomatic Scala
set get should return None for empty sets. fix bug with set members get
a more idiomatic way to define injections
tests for sorted sets
codestyle
Remove use of AtomicLong and make thread-safe

Place a lock around the merge operation to ensure the merge
operation is thread-safe. Use a java.util.concurrent.ConcurrentHashMap
as the backing store to make get/put threadsafe
Merge branch 'develop' into redis-sorted-sets
Move mergeable to Semigroup
Fix tests for sparse stores
another attempt at fixing the tests
Fix up MonoidStore
Fixup the Monoid -> Semigroup change
Merge branch 'develop' into redis-sorted-sets-part-deux

Conflicts:
	storehaus-redis/src/main/scala/com/twitter/storehaus/redis/RedisSortedSetStore.scala
Merge pull request #165 from twitter/mergeable-semi

Move mergeable to Semigroup
Updates files for new sbt
Merge pull request #146 from sharethrough/add_jmap_backed_mergeable_long_store

Add Java HashMap backed Mergeable Long Store
Make MergebaleJMapStore conform to new API