Allow vic20/c64/c128 to share user port devices, removed c64 version of vic1011 and moved protovision 4 player adapter from bus/c64 to bus/vic20. Tried to test with http://code.google.com/p/commodore-multi-player/ as it supports protovision 4 player adapter, but it currently crashes. I have had to disable 1541 as it prevents quick loading from working. [smf]