corrected scope for if/el
removed old file logger
use python logging

- logging is now done with the logging framework
- the old file logger has been replaced with standard logging
- webserver.py is responsible to configure logging handlers
- logging configuraiton in glastopf.cfg
fix missing import/logger
consistency in configuration options
change in config file
minor corrections based on feedback
Merge pull request #21 from johnnykv/master

Proposal for issue #20 (logging).