The following options are missing:
	[no]optimize	- affects screen redrawing method
	[no]redraw	- simulate character insertion by redrawing line
	[no]slowopen	- don't use character insertion
	tags="tags"	- list of tags, used as TAGPATH

I'd like to improve the versatility of the options whose value is a command:
cc, make, kp, and ep.  I'd like to add some notation that allows you to say
where to insert the current filename or current word.
-------------------------------------------------------------------------------
Currently, elvis is configured to look for | only in .exrc files.  It doesn't
look for | in any interactively entered command lines, yet.
-------------------------------------------------------------------------------
The 'p', '#', and 'l' flags aren't supported.  Also, ex commands don't accept
counts; e.g., ":c5" can't be used to change five lines. 
-------------------------------------------------------------------------------
BIG JOBS:
  Desirable extension: merge input mode and visual command mode.
  Display long lines by wrapping, like the real vi (if ":set sidescroll=0")
-------------------------------------------------------------------------------

- In the ":w >>filename" command, elvis doesn't allow any whitespace between
  the ">>" and "filename".

- Elvis doesn't allow "backslash newline" inside a single EX command.

- VMS intercepts the control-T character, which is normally used to increase
  indentation.  The <Tab> key works, but it doesn't do quite the same thing.
  (":map! ^I ^T" helps.)

- Under VMS, file I/O is very slow.  Looking over the vmsio.c file, I get the
  impression that it is rather over-done for elvis.  Its speed could
  probably be inproved.

- The errlist feature doesn't seem to work with the Borland compilers.  Perhaps
  they write to stderr instead of stdout?  This will probably be easy to solve
  once I modify the "cc" and "make" options, as described earlier.

- File preservation is still flakey.  On DOS/TOS/VMS systems, it is also more
  complex that it should be.

- The act of appending to a cut buffer (as in "Ayy) sets file modification
  flag.  It shouldn't!

- On systems that have a small stack, the .exrc file is limited to BLKSIZE
  bytes -- 2048 on most systems, but 1024 on Minix-PC, Coherent, and MS-DOS.
  Also, .exrc can't :source other files.

  On systems that allow a large stack (including most UNIX systems), the .exrc
  file is still limited -- to 4096 bytes, though.

- On some terminals, the :ti=: string switches the display from one page
  to another.  Since the "Press <Return>..." prompt is displayed after
  this string is sent, the pause doesn't achieve its desired effect:
  it doesn't let you read the output from the program you just forked.

- It would be nice to look for SYSEXRC in the same directory as the
  executable on DOS systems, and if "alias.c" looked for ELVIS.EXE in the
  same directory, too.

- Some unreliability with ^Z?

- "dtA" (on a line with no "A") doesn't beep.

- Character class matching doesn't support "ignorecase".  Should it?

- "d)" don't work correctly at the bottom of a file.
