fixed NPE.

Some entities corresponding to 'key' might not exist in datastore nor memcache because most queries return result with evantual consistency.
if in that situation, NPE raised in entity.getEntity().
removed batchGet.containsKey(key)
Merge pull request #15 from zaki50/fixNPE

fixed NPE.
Merge pull request #16 from zaki50/remove_containsKey

removed batchGet.containsKey(key)
Moved Settings class to AQCS (inner class)
Fixed option name typo
Changed class modifier about Strategy interface
Fixed broken test
Changed class modifier about Pair class
[maven-release-plugin] prepare release memvache-0.3.6
[maven-release-plugin] prepare for next development iteration
Merge branch 'release/0.3.6' into develop
Adhoc patched, fix NPE in GetPutCacheStrategy
Adhoc patched 2, fix NPE in GetPutCacheStrategy refs #17