Modifying the image processor to optionally add imported images to the database

A proposed solution to #114. Note that this does not yet allow the user to specify an alternate media db, it just uses the db that Magmi is configured to use. Since it uses the target file, it should work with remote images as well as local images.
Interesting and also annoying, but at least saving images to the DB means that you can lose the contents of the media directory at any time and not have a problem. I guess the file system media directory becomes a local cache to reduce database hits.

How would you like me to proceed?