* Implement NO$GBA debug registers.

NO$GBA comes with 4 debug registers that allow a ROM to print text to
the emulator terminal and 2 other status registers, one with the name of the
emulator and the other with the clock cycles count. This commit
implements them for the ARMv5 processor.

Some small things to note:
 - `NocashPrint` was changed and now it takes an address to _the string_ instead of the flags before it (those
don't do anything anyways).
 - The "Emulation ID" register contains the string "melonDS " followed by version, _not_ "NO$GBA"

* Fix styling issue and improve comment regarding NO$GBA message flags