* app/brush_select.c: make the edit button active if the default
 	brush is a generated brush.  Make sure brush spacing >= 1.0
	* app/gimpbrushlist.c: do not add a brush to the brush list if it
 	failed to load
	* app/gradient.c:  Fix typo that caused a crash with --no-data
	* app/main.c: be more forgiving of fp rounding in gserialize tests