release-1.0

This release features a bunch of internal changes to the Z80 codebase, most notably a number of optimizations relating to the use of the ix register.

There were some minor changes to the text, and internal details, but the biggest visible difference is the introduction of "widescreen output". The ZX Spectrum's text-mode is limited to 32 characters in width. Via the use of a custom text-drawing routine, and a tiny font, the game now outputs 64-characters of text per line.

The game feels a little more cramped, but the poor word-wrapping of the previous release is now less significant.