Log rewrite

[infeeeee]

Final part of #90

• Full rewrite of logging using the standard logging library, different log format for file and and console logging. Log levels follow standard conventions.
• Log rotation: only the last 5 files remains, older files automatically deleted
• Log settings in the configurator menu:
  • Console log level
  • If Console log should include time. Reason for this, if IoTuring is run as a service, the system log already adds a timestamp.
  • File log level
  • Enable/disable file log
  • Change the log dir
• Settings are loaded twice with ConfiguratorLoader, this way logging can start before Configurator menu opened. File logging does not start before configuration loaded, early messages saved to a buffer, and saved to file only if file logging is enabled.
• Terminal related functions collected in TerminalDetection.py

It's working, but it's possible that there are some bugs.

Fell free to edit if you have some better ideas.

resolves #58

[richibrics]

Finally we're using logging :) Also great work with the settings for the log. Thank you so much