Optimized the sprite editor for usability

Rearranged buttons for ease of use, set empty defaults for loaded
images, set true for loaded images by default, removed unneeded features
and buttons, set save sprite button to auto refresh the sprite after
offset settings have been filled in to remove need for refresh every
time, set sprite to clear after being saved to remove need to click
clear button, and set default load and save dialog windows to go to
unpack directory automatically to save clicking every time.