PROGRAM
	include: include copies of subfiles
USAGE
	include
DESCRIPTION
	include copies its input to its output unchanged, except that each line
	beginning

	#include "filename"

	is replaced by the contents of the file whose name is filename. included files
	may contain further #include lines, to arbitrary depth.
EXAMPLE
	To piece together a Pascal program such as include:

	#include "include.p"
BUGS
	A file that includes itself will not be diagnosed, but will eventually cause
	something to break.