Merge pull request #1 from sergey-dryabzhinsky/add-p7zip-cmd-tool-support

Add p7zip cmd tool support
New image formats

- add support for almost all readable by PIL 1.1.7 image formats
- add some new formats from Pillow
Merge pull request #3 from sergey-dryabzhinsky/detect-pillow-image-decoders

Add support of many PIL/Pillow formats - By sergey-dryabzhinsky@github