begin refactor, set up segments
set up stack frame and call for print ui
implemented first 4 characters of print ui
first nibble of location is printed
full location is printed, in theory
switched from cx to bx for holding location

Also printed 2 more ui characters.
finished prompt print procedure
parse backspace
parse 'h' and 'l'
removed backspace parsing

Backspace is unnecessary when random cell access is available, at least the way it was to be implemented.
finished parse procedure

(excluding actual call addresses)
implemented next cell procedure
implemented prev cell procedure
cleanup and some bug fixes
implemented edit cell procedure
implemented write procedure
fixed missing boot signature
merged boot2.hex into boot.hex
deleted boot2.hex
Merge branch 'get-a-ui-part-1' into develop