new function: mkstrm

	mkstrm(p,len)

	Mkstrm returns a string backed by the len byte
	range of memory in the calling process starting
	at p.

the definition of not is expanded to all values:
  not(0)   -> 1
  not(nil) -> 1
  else     -> 0

symbols beginning with @ can be constructed like other symbols:

	; '@foo;
	@foo