use a predefined pool for keyspace ops

Obscure bug involving 'fake' keyspaces being visible

* A pool is spun up for each keyspace
* If a keyspace doesn't exist, but is 'used' (e.g. describe_..)
        then the pool is spun up
* This causes subsequent requests (after the pool is created)
        to fail, since the pool is dangling
* The solution is to use a predefined pool for all keyspace ops
        and to start this pool up if it doesn't exist


NOTE:   I couldn't actually get the tests to run - the latest develop is barfing on my laptop w/ ```combonodefinder.app not found```, but that could very well be the horror that is Mavericks.