Fixing false assumption in TuneCassandra. Previously, there was logic to guard
against yaml config settings that had been added or removed from different versions. This was tested
by adding a null check to see if the setting existed in the yaml that was read in. Unfortunately,
if a property was commented out in the yaml (yet still compltetly valid as a setting) the entry would
not be present in the map that snakeyaml produced, and hence you could never write out that setting.
Basically this was a poor man's way to avoid branching. Now that we branch in priam, that is no longer necessary.
Merge pull request #160 from jasobrown/1.1

Fixing false assumption in TuneCassandra regarding setting compatibility. Reviewed by sloke