Batched store goodness
- add BatchedStore for writes: #175
- MySQL batched multiPut: #173
- MergeableMemcacheStore: #182
- Writeable stores: #180
- Add readme notes for memcached tests: #184
- Add the Mergeable type: #183
- MergeableMySqlStore and MySqlLongStore: #181
- PivotedStore: #186
- Make twitter util provided: #190
- Remove version file: #194