Improve module support/tolerance for 64/256 grids

[Dewb]

The Rack versions of the modules inherit the hardware support for non-128 grid models. Firmware changes will be necessary to complete the module/device support matrix.

• white whale adjusts to 64 but does not use 256 scanner-darkly mod here
• earthsea accepts keypresses from 256 but does not adjust size or give LED feedback on second half
• earthsea does not adjust to 64; play position and knob indicators scroll off grid
• meadowphysics does not use second half of 256, presses on second half do strange things
• meadowphysics does not adjust to 64 -- not much to sensibly do here
• teletype supports series/mext 64 but not 40h