DERBY-5886 FILE_CANNOT_REMOVE_FILE exception prints garbage. 

Added new messages to cover cases where no exception was available for
the second argument, and made text of those messages more specific to 
the actual usage.  Fixed the calls in RAFContainer.java to be consistent, and
still use original error.



git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1469505 13f79535-47bb-0310-9956-ffa450edef68