impl: pencil tool
impr: track pencil actions for undo
impl: shape strategy
deb: clone canvases, style update
impr: shape strategy when zoomed
impr: pencil strategy
added shape submenu
Merge branch 'master' of github.com:notiontaxi/pixelshift
implementations for shape drawing
ref: shapeStartegy
deb: multiple filters at one time
deb: shape movement on zoomed canvas
commOut: shapeTool - line