Config is now safer (can only fail if no valid config was ever provided), and LoadingScreen does not returns to MainMenu in that case
remove interface/Settings and adapt interface to Config
Error Messages
Merge branch 'master' of https://github.com/VLanvin/GL_MPRI_2014
Merge pull request #136 from GL-MPRI-2014/config

Config
add to_string and from_string functions to Config for tiles, unbount_units, settings and Battlefield
Merge branch 'master' into script_dev