Adjust custom brush on the fly

[novemberist]

I love aseprite, but one of the things that i feel it lacks in comparison to other great pixel editors of old (dpaint, brilliance, grafx2) and that still makes me go back to them often in frustration, is the ability to adjust a custom brush after it has been created. I think it would really greatly improve some people's (at least mine) workflow if you could quickly rotate, flip, scale, shear etc. the active brush and be able to change the position of the brush handle.

[dacap]

Added some support to flip and rotate brushes in v1.3-rc7 using Space+X or Space+H, Space+Y or Space+V, Space+D, Space+R