Changes
/* History */ Added info on differences between BASIC 1.0 and BASIC 1.1 in using DATA statements
* DEC$ bug removed (in BASIC 1.0, it required two opening brackets and was undocumented)
* Better handling of string arguments to RSXs (|DIR,"*.BAS" rather than a$="*.BAS":|DIR,@a$)
* DATA statements can appear anywhere within a line; in BASIC 1.0, they had to be at the end of a line
* FILL command (fill area with solid colour)
* COPYCHR$ function (fetch character from screen)
