Add animated GIF splash support

[Epicpkmn11]

This adds animated GIF splash support and cleans up the main file a bit (it looks like more that it really is as I moved a lot of stuff around)

GIF details:

• Most GIFs up to 256x192 and less than around 10MB (more than you should ever need) between both images should work
  • Smaller GIFs will be centered
• GIFs up to 1MB will be decompress while loading and should all display at full speed, GIFs larger than that may play a bit slowly since their decompressed while displaying
• If both screens loop indefinitely (or aren't GIFs) then they will be shown for 3 seconds (same as before)
• Otherwise they will be shown until both GIFs have completed their set amount of loops, if one finishes first it will wait on the last frame
• The user input flag is supported and the GIF will pause on that frame until any button pressed
  • Did you even know GIFs can pause until input? Like nothing supports it ;P
  • Edit: As of #17 it will wait until any button is pressed or the delay on that frame runs out, so if you set a 1 minute delay it will wait 1 minute or until a button is pressed
• Interlaced and text GIFs are currently not supported
  • Text because its so rare I couldn't even find a tool to make one
  • Interlaced because it doesn't seem to provide any major advantages (all fields seem to be supposed to be shown at once?) and would be kinda annoying to do I think ;P
• TL;DR all vaguely normal GIFs should work (and even some weirder things) ;P

Misc:

• BMPs are still supported and now any up to 256x192 will work
• It will check for GIF, then a BMP, then if neither are found it will use the default splash for that screen
• Switched the GRIT images to be bitmaps instead of map and tile since that's easier to display
• A couple changes to the Makefiles and .gitignore
• Rearranged main.cpp a bit, but mostly only the graphics related things have changed
• Switched to tonccpy intead of vramcpy_ui

Todo:

• [x] Make sure it still actually works
• [x] Maybe try to improve speed

[Epicpkmn11]

Alright, I made it decompress GIFs up to 1MB while loading instead of while displaying so now it can display all GIFs I've tried (up to 1MB) at full speed so I think this is probably good.

Here's the GIFs I tested with:

• Newton's Cradle, has small animated areas so this worked fine even while decompressing while displaying
• Spinning earth, only the earth is animated so this is also pretty light
• Earth ring thing, the whole image is animated pretty fast so this was slow before
• Cardcaptor Sakura OP1, this is about as big as you can use, since its way to big to fit in RAM decompressed it still plays a bit slow
• iQue top splash, from TWiLight, this waits for user input on the last frame
• Japanese H&S message, from TWiLight, loops forever