Add some command-line interfaces for use w/ makefile

Extras:
-function to dump trainer pals
-fix testing leftover in a compression function
-keep load_rom() from getting in the way (relative address breaks extras)
Dump and include trainer palettes
Move compressed trainer pics into the main folder
Allow png->lz compression in the build process

To enable, append '${IMGFILES}' to line 22:
pokecrystal.o: pokecrystal.asm constants.asm wram.asm ${TEXTFILES} ${IMGFILES}

Also append '${LZFILES}' to line 48:
	rm -f main.tx pokecrystal.o pokecrystal.gbc ${TEXTFILES} ${LZFILES}
Don't try to convert empty 2bpp files

Also, make non-square images 1 tile wide
Minor path fixes and cleanup
Infrastructure to dump pngs for 2bpp graphics
Dump cry headers
Add build target to mass-generate pngs from 2bpp files
better dimension handling in 2bpp->png
Remove unnecessary 2bpp files

These can be generated using gfx.py and are non-essential to compile.
This reduces the size of the repository significantly.
Fix compressed graphics and filestructure

-No more /lz folders.

-Fixed some lz files that didn't have terminators
  An extraction error caused some lz files in gfx/misc/ to lack
  terminators. These slipped through the cracks since they were
  surrounded by incbins calculated from the filesize, and the
  original decompression was done from the baserom, where
  terminators were intact.

  There might be more offending lz files.
Finish off make target for png generation

Now any existing lz files are converted to 2bpp, and all 2bpp files
are converted to png.
Clean up the makefile a bit

Simplifies/explains png import
Merge pull request #108 from yenatch/master

png->lz and palettes