MMC3 mapper not fully compatible or errorfree.

[nIghtorius]

Fails MMC3 tests.

• details.nes, test #7
• a12_clocking, test #5
• scanline_timing, test MMC3 mapper not fully compatible or errorfree. #3

Games that do not work:
Fire Emblem - Ankoku Ryuu to Hikari no Tsurugi (Japan) -- Intro works, description of units work. But actually starting it locks up with a black screen.
Wario Woods (MMC3) - Screen not fully rendered after rework MMC3 (but the previous bug of not drawing the critters and bombs seems to fixed after the MMC3 overhaul)

sprite_hit_tests_2005

• fails 07_screen_bottom.nes, test #7 (Should hit; sprite pixel is at 238) <-- this is a regression.

firehawk.nes (camerica)

• Glitches during gameplay. Seems to be color attributed based. Timing issues?