always priming database, and changed prime script to be idempotent
always creating zookeeper data directory, not just on clean deployments
not creating cassandra data directories on image creation, and also erasing cassandra /zookeeper directories themselves on clean
only converting datastore flag to bool if it is a string
merged with testing
undid reversions from merging with testing
added in code accidentally removed on the revert
Merge pull request #640 from shatterednirvana/persistence-finally

Persists data across AppScale deployments (virt cluster only)