Z80 emulation updated

Hi!

Here's an update to Stuart Brady's ZX Spectrum system emulator, fixed to work with the code in CVS, with some dead code removed, implementing HALT (and a hack that makes the Spectrum ROM use it in the input loop), and with support for loading snapshots ("-kernel commando.z80" :) using libspectrum. (Be sure to compile with --enable-libspectrum.)

CU
Uli

SUSE LINUX Products GmbH, GF: Markus Rex, HRB 16746 (AG Nürnberg)