build: clean cmake file
build: add debug and release specific flags
logger: enable compiler to trim log->debug() and log->spam() as no-op outside of debug mode.
Logging: Updated readme.
Loglevels: Fix CMAKE optimization flags
Loglevels: Fix NullStream declaration.
Build: Don't stomp on default build flags.
Build: Add missing $s in used CMAKE_FLAGS variables.
Logging: Update MDNetworkParticipant to use MessageDirector Logger.
Logger: Have all logging be passed through LogCategories, removing cruft from gLogger.
Merge pull request #43 from OpenOTP/loglevels

Add compile-out support for "Debug" and "Spam" levels so we can use them freely (and excessively).