Bump pokemontools for gfx handling.
Simple graphics handling in the makefile.

Two-way conversion invokes circular dependency warnings, and is outside the scope of the build.
Now it's one-way.
Monster pic dimensions in filenames.

While we're here, add the .2bpp root extension too.
Move monster pics from numbered directories to named ones.
A couple more EvosAttacks references.
Fix image extensions in gfx/{credits,misc}.
Image extensions in gfx/{intro,title}.
Image extensions in gfx/tilesets.
Image extensions in battle animation graphics.
Image extensions for trainers.
Rename trainer pics to use names instead of ids.
Merge pull request #242 from yenatch/master

Redone graphics handling and renamed pics.
Fix a title screen label that accidentally made its way into bank 1.

Somehow, a title screen (bank 0x43) function had its label put in bank 1.
This caused changes to either bank to break the compiled rom.

fixes 61a3d145
Unused title screen code, graphics, tilemaps, palettes.

At 43:4000 (UnusedTitleScreen) is a semi-functional title screen.
It's never used, and appears in the Japanese version at the same offset.

Notably, a portion of the logo is cut out and used as OAM.
The final title screen instead uses BG priority to avoid this.
Merge pull request #243 from yenatch/master

Fix bank 1. Found a scrapped title screen.
Better labels for drumkits.

Also use noise commands for instruments.
Field effect data and sound effects.
Magnet Train data.
Anonymous jumptables and sfx in bank 23.
Merge pull request #244 from yenatch/drumkit

Magnet Train and drumkits.