Terminal emulation

[Blacklord]

Goes without saying, but we obviously need to support the usual suspects - ANSI (VT102), ASCIII (VT52) & CG, do we also include AVT/0 (Avatar) ? My thought is yes, because it is an optimised ANSI & we are trying to wring performance out of this project.

However, I'm not sure if the source code for Avatar is available & if it can be made to 'fit' the 128.