Upload update

I just added a couple new features to the upload page.
You can now upload .jpg, .bmp, .gif, or .png image files and it will automatically compress the file to a small sized jpg so that it downloads fast and takes less web storage.
It will rescale images larger than 800x600 to be 800x600 (or whatever necessary to not stretch the image) and leave images smaller than that the size they are (so not to stretch them).