* logger: added log_warn/WARNING_MSG which will print a warning in the log and console (needed something between error and debug)
 * logger: log_msg/SIMPLE_MSG will no longer print the .cpp file and function name (as the name suggests, this is supposed to be a simple msg)
 * proper config.logging.verbosity handling (cast from the enum, don't just use a number ...)
 * added FLOOR_FULL_VERSION and FLOOR_COMPAT_VERSION macros (first expands to 0.1.3-d1 and the second to 0.1.3)
 * some header fixes