If there's no '.', just pass the command to po, and evaluate the first 'key', to allow for some slightly more complex behaviors.
PEP8: E711 comparison to None should be 'if cond is None:'
PEP8: E713 test for membership should be 'not in'
PEP8: E203 whitespace before [,:]
PEP8: W293 blank line contains whitespace
PEP8: W291 trailing whitespace
PEP8: W191 indentation contains tabs
PEP8: W292 no newline at end of file
PEP8: W391 blank line at end of file
PEP8: E225 missing whitespace around operator
PEP8: E226 missing whitespace around arithmetic operator
PEP8: E251 unexpected spaces around keyword / parameter equals
PEP8: E231 missing whitespace after ','
PEP8: E703 statement ends with a semicolon
Remove superfluous if parens
Replace Ivar casts with void * casts
bmessage: use regex breakpoint to match category

Resolves #57
Add "Dancing in the Debugger" link to README
Fix typo and formatting
bmessage: Allow optional category