- Added debug_policy_t helper. Allows compile time change of debug
  status on a class via include.
- Added LOGGER define as well as policy-based Logger.
  The define will allow one to easily use the default-setting for
  logging. If only really wants to log more, they may say
  Logger<VERBOSE>::verbose().
  This logger is exposed as an ostream.
  LOGGER::error() goes to cerr and the rest go to cout by default.
  Could adjust this to go to files, etc for the non-warning levels.

Conflicts:
	src/graphics.cpp
	src/main.cpp