Stable new version with layers.

MILF sketcher variant:
+) Drawing on layers, with own separate undo history, and no global.
+) Save/load layers along with flat image, backward compatible with DFC.
+) Load flat images, saved to memory or drag'n'drop from disk, as new
layers.
+) Floating toolbar panels.
+) Transparency overwriting shape tools for erasing.
=) Pan/zoom/rotate visible canvas with CSS3.
Tested on Opera v12.17, Firefox v31.0, Chrome v34.0. Fails on IE9.