Unofficial backup of vasm http://sun.hasenbraten.de/vasm/

Several patches are in progress ; they are related to the configuraiton CPU=z80 with SYNTAX=oldstyle. Each patch is within its own branch.

• column allow to use : in order to have several opcodes per line
• outofrange fix some issues with 8bits maths computed on 16bits
• zshcompletion write a zsh completion script to ease the use of vasm