Driver for the Hitachi HD44780U dot matrix LCD controller

- Only 4bit parallel interface supported for now
- Write-only operation (RW pin should be connected to ground or held low)
- 1 or 2 line LCDs supported with 5x8 or 5x10 dot fonts.
- Support for creating custom characters.
Ah yes, I forgot to double check that. On the other hand I really think using `panic!` is the right thing to do in Zinc, if it's not customizable enough to generate the code we want I think we should bring that up with the rust devs.