cleanup image save dialog aesthetics

cleanup image save dialog aesthetics
ticket:96
one of the problems is that when people try saving an image they
couldn't find where the image was saved too. This is probably because
they didn't set a file name and no errors were thrown.

this patch ties the "save as" prompt to the save button, so once someone
gets the pixel size right they have to chose a filename.

I also fixed the problem where it wasn't loading the "lock aspect ratio"
icon out of the resource file, and made a few other aesthetics updates.