Configuration file consolidation patch from Moses McKnight.

* Create GetNewConfig() and GetKicadConfigPath() to unify configuration file
  creation and location.
* Move Windows configuration out of the registry into configuration files.
* Move Linux configuration files from $HOME to $HOME/.config/kicad to eliminate
  configuration file pollution in the users $HOME folder.
* Fix a bug in the configuration file where the Eeschema hot keys are saved.