Adding Clone method.
Merge branch 'master' of github.com:gosexy/canvas into experimental
add OpenBlob : reads an image or image sequence from a blob.
add Contrast and SigmoidalContrast
fix TestOpenBlob hardcode issues
Merge pull request #2 from Terry-Mao/master

Adding OpenBlob
Fixing broken package on ArchLinux.
Fixing #3, *Canvas should have been passed by reference from the beginning.
Applying 7b41a76 from Terry-Mao.
Merging d8b6034 from Terry-Mao
Merged Blob(), SetFormat() and memleak fixes for Error(), from Terry-Mao.
Adding benchmarks that need to be improved.
Better description of Thumbnail()
Merge branch 'master' of http://github.com/gosexy/canvas

Conflicts:
	canvas_test.go