Fixes some error handling for f5_cccl.resource.Resource
Fixes some error handling for f5_cccl.resource.Resource

Problem:
* AttributeError was given when a delete() a second time
* Improper handling of iControlUnexpectedHTTPError

Analysis:
* str(error) was used rather than implicitely looking to message
 * Handler
* Set up a handler for AttributeError to raise *DeleteError

Tests:
None in this commit

f5devcentral/f5-cccl,f5devcentral/f5-cccl,ryan-talley/f5-cccl,richbrowne/f5-cccl,ryan-talley/f5-cccl,richbrowne/f5-cccl