Disable [ESC] as meta-key in Viper

[Matt Bohy <matt.bohy@gmail.com>]

Hello,

I hope that I haven't missed something obvious, but I'm having a lot of
trouble with [ESC] (or, as I actually type it, CTRL-[), being
interpreted as the meta key in Viper.  I understand that for some
people, having the escape key work as the meta key is important, but I
have an appropriate meta key.  I'm coming from vi/Vim, and I type fast
enough that I often get errors when I try to escape out of insert mode
to do something else.  Common examples include: M-:, which in Emacs
enters Lisp Evaluation mode; M-u, which converts a word to uppercase;
and M-j, which inserts a newline at 'point'.

I've tried fiddling with several options, including
viper-ESC-keyseq-timeout, to no avail.  Ideally, typing ESC (or
CTRL-[) would ONLY be used in Viper to move from insert mode to command
mode.

I hope that there's an easy solution to this.  I've otherwise been very
impressed with Viper, and I'm excited at the prospect of having the
'Best Of Both Worlds' in an editor!

Thanks in advance,
  -- Matt