Fix build with go1.2
Add function to get image format
Merge branch 'fix-compilation-with-go1.2'
Refactor the name of the getter to be more coherent
Add a getter and setter for the image type
Add binding for MagickStripImage
Merge branch 'add-strip-function'
Merge branch 'add-getter-image-format'
Add image types as constants
Merge branch 'image-type-getter-and-setter'

Conflicts:
	canvas.go