This is version 3 of the editor. It is too large to fit on a pdp-11
unless you have overlay code. (Such code is available for v7 unix on 2bsd.)

Version 2.13 corresponds to version 3 without the enhancements in 3.
There is no reason to use 2.13 unless you have a pdp-11 that does not have
overlay software, since 3 contains all the bug fixes and some new features.

Special installation notes for this version.
2) The include file varargs.h should be installed, as the printf here needs it.
3) The include file local/uparm.h should be installed, as ex_tune.h needs it.
   The contents of this include file can be modified if you wish to place
   the editor in a nonstandard location.

Conditional compilation flags:
	-DTRACE		for debugging (wont then fit on an 11)
	-DVFORK		for UCB Vax/Unix or 2.9 BSD with the vfork system call.
	-DCHDIR		compile in undocumented old chdir (cd) command
	-DLISP		compile in lisp hacks
	-DUCVISUAL	compile in code to handle \ escapes for visual on
			upper case only terminals.  gross.
	-DCRYPT		-x option to edit encrypted files