X atoms rework

[Julien Danjou]

I've been hacking in xterm.c this days, and saw some things I did not
like that much about the handling of X atoms.

Therefore, I rewrote this part, and here's a set of patch that enhance
things a bit.  It should make X initialization faster over the
network, at least, and stop requesting atoms that Emacs should already
have locally.

-- 
Julien Danjou
// ᐰ <address@hidden>   http://julien.danjou.info