Add in automatic name-space cache flushing
SwatDBDataObjects should implement getCacheNsArray() to return an name-spaces that should be flushed.
fix docblock
better formatting/docs
Updates for Mike's comments:
 - improved documentation
 - add SwatDBFlushable interface for SwatDBDataObject and
   SwatDBRecordsetWrapper
more documentation formatting updates
Merge pull request #18 from nburka/flush-cache

Add in automatic name-space cache flushing