message: Add config=trace to Makefile
  This will make it easier to analyze trace output without changing
  code...
diff: @@ -31,6 +31,10 @@ ifeq ($(config),iphone)
  LDFLAGS+=-arch armv7 -arch arm64 -L $(IPHONESDK)/usr/lib -mios-version-min=7.0
  endif
  +ifeq ($(config),trace)
  + CXXFLAGS+=-DTRACE=2
  +endif
  +
  ifeq ($(config),release)
  CXXFLAGS+=-O3 -DNDEBUG
  endif
  