Snapper for Firefox 3

Snapper, a wonderful Firefox extension, was developed for older versions of Firefox (<= 1.5) and even with install.rdf patching it would run on Firefox 3 with glitches that made it almost unusable. I hacked the code a bit to provide a nice version of Snapper for Firefox 3.

Major fixes:

• Fixed bug with selection process when page elements were actually selected when dragging the screenshot area.
• Fixed bug with dimensions so that the red border is not included in the screenshot.

If you have some suggestions for more quick fixes for Snapper, please comment.