Add .gitignore and change the :clx/:tty selection to a context keyword vs display.
Translate remaining termcap references to terminfo.  This doesn't make
it right, but it gives me some targets to knock down when attempting
to compile.

The next stage is apparently going to be ripping out the dependence on
the serve-event logic that is embedded in CMUCL and SBCL.  Based on a
bit of research on the SBCL devel mailing list, it's an old crufty
potentially dangerous interface.