INES Mapper 202

Implemented in BizHawk as of commit f72875b584abd79201ad9d3d0131fa5afcf0c429

Used for the 150-in-1 pirate cart.

 Registers:
 $8000-FFFF: A~[.... .... .... O..O]
               [.... .... .... RRRM]
 
 
 O = PRG Mode, if 3, will use 32 PRG mode, else 16
 R = Page registers, used for both CHR 8k banks, and PRG banks (in both 16k and 32k modes)
 M = Mirroring, 0 = Vertical, 1 = Horizontal
 
 CHR Setup:
 
                    $0000   $0400   $0800   $0C00   $1000   $1400   $1800   $1C00 
                   +-------------------------------+-------------------------------+
 CHR-ROM:          |                             { 0 }                             |
                   +-------------------------------+-------------------------------+
 
 
 
 PRG Setup:
 ------------------------------
 32k Mode:
 
 $8000     $A000     $C000     $E000
 +-------------------------------------+
 |                 {0}                 |
 +-------------------------------------+
 
 
 16k Mode:
 
 In 16k mode both regions are mapped to the same PRG bank
 
 $8000     $A000     $C000     $E000     
 +--------------------------------------+
 |        {0}        |       {0}        |
 +--------------------------------------+