clear containers before we use them rather than after, so that in the case of
exceptions we can recover.

closes #127

[core, Cassandra, gemfire, mapkeeper] Fixing squid:S2864 -  "entrySet()" should be iterated when both the key and value are needed

[cassandra cassandra2 dynamodb hbase098 hbase10 jdbc s3] Fixing squid:S1481 - Unused local variables should be removed

Replaces numeric status codes with a canonical set of Status objects,
each with a short name and description.
Bindings with more specific errors (e.g., timeouts) return additional
statuses.

This changes the default output from messages like:

   [UPDATE], Return=0, 511

To:

   [UPDATE], Return=OK, 511

The CassandraCQL client defines a number of

* Changes the default port to 9042 (this is the default CQL port).
* Changes property "host" from a space-separated list to property
  "hosts", a comma-separated list.
* Updates a few messages.

This includes changes to main pom for the v1.2.9 cassandra driver.

closes #145