Use consistency helper to extract timestamp from message
Merge branch 'master' into manu-tracking-tx-recording
Reset mry transaction before returning result.

This ensure the transaction operations are not holding storage reference anymore and that the transaction is serializable.
Merge branch 'master' into manu-tracking-tx-recording

Conflicts:
	mry-core/src/main/scala/com/wajam/mry/Database.scala
Merge pull request #68 from wajam/manu-tracking-tx-recording

Changes for transactions logging