On OS X, this broke Cmd-V to paste in the text boxes.  Apparently wx
thinks having mnemonics (which are Alt-* on Windows) be Cmd-* on OS X,
even if this disables standard shortcuts, is a good idea.

Lioncash suggested just getting rid of the accelerators on non-menu
controls, so I'm doing that rather than disabling them only on OS X.

The PowerPC CPU has bits in MSR (DR and IR) which control whether
addresses are translated. We should respect these instead of mixing
physical addresses and translated addresses into the same address space.

This is mostly mass-renaming calls to memory accesses APIs from places
which expect address translation to use a different version from those
which do not expect address translation.

This does very little on its own, but it's the first step to a correct BAT
implementation.

They point to the same contents, so there's no reason to use the
mirror. This lets us make all the mirrors static.