Add cmdline flag for easy log-config
Add cmdline flag for easy log-config

This adds a new cmdline-flag '-L', that allows to define log-levels
for single loggers by their qualname. If you instantiate the logger
via ``logging.getLogger(__name__)``, this is the modul name, e.g.:
'pyethereum.wire'.

ebuchman/daoist_protocol,ethereum/pyethereum,karlfloersch/pyethereum,harlantwood/pyethereum,inzem77/pyethereum,holiman/pyethereum,shahankhatch/pyethereum,vaporry/pyethereum,jnnk/pyethereum,pipermerriam/pyethereum,pipermerriam/pyethereum,ebuchman/daoist_protocol,ckeenan/pyethereum,shahankhatch/pyethereum,ethers/pyethereum,ethereum/pyethereum,ethermarket/pyethereum,ddworken/pyethereum,karlfloersch/pyethereum