Changed location of config file. Also added a DEBUG, INFO and ERROR macro.
If the compile flag "debug" is given in the compile options (in the rebar.config) then this flag is enabled and the macros are expanded to an io:format. If the flag is not enabled then the macros is expanded to 'true'. This construct makes it possible to have a debug mode, which would print all of the debug messages, while still having low performance impact when we don't want to run debug mode.