fix smudge+ brush crashes (rounding problems due to floating point math)
fix smudge+ brush crashes (rounding problems due to floating point math)


svn:9a0661a51fa546353b2044a64a194520c6caa5ad@237

achadwick/libmypaint,b3sigma/libmypaint,b3sigma/libmypaint,b3sigma/libmypaint,achadwick/libmypaint,achadwick/libmypaint,achadwick/libmypaint