* app/gimprc.c
	* app/gimprc.h
	* app/ink.c
	* app/paint_core.c
	* app/preferences_dialog.c: Now the perfect-mouse-tracking
	normally enabled by pressing MOD1 is a preferences option,
	and MOD1 inverts the affect.

	* app/ink.c: Mildly tweaked the default brush size/range for
	my own twisted sense of esthetics.  Forgive me.