[dwm] [dvtm-pull request] Fix for the alt keystrokes

Hi,
   i was frustrated to not be able to use my usual
alt+<n> keys combination in WeeChat, ELinks, bash,
and so forth. This due to a problem related to the
way dvtm handles the input which forced me to type
another key before the alt+<n> have any effect.

I decided to try to solve the problem by playing a
bit with the code and finally i found a way, here.
I hope it's a solution (not an hack) which, maybe
with some change, may work without cause any other
problems. At most it works great here!

Now i'm able to use alt+<n> with bash, alt+r which
clear the current line, using "unlucky" ELinks key
combinations, hub the channels on WeeChat (and
irssi) and so forth. Also there is a new (useles?)
constant ESC which may be used in config.h or so.

The pull request is very little (only three lines) and it
is based on the latest release rather than the dropbox
one. Any improvement of course is very appreciated.

Hope this helps.

-- 
Claudio M.
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N+@ o--> K? w+@> O-@> M- V? PS+@ PE+@ Y+ PGP> t(-)@ 5?
X+ R? tv-- b+> DI-- D? G e+@> h--@> r y*
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