Saving RAM words to Flash

[mkobetic]

Assuming words are generally relocatable, there are two main issues with moving a colon word from RAM to flash

1. An XTs pointing at RAM word must be replaced with XTs pointing at the same Flash word
2. RA4M1 doesn't allow writing into code flash with code in the code flash. So the flash writing code must be relocated into RAM and run from there.

RA4M1 code flash is erased in 2K blocks and written in 8byte chunks.