Ping: canonicalize type names on input / output

[Tom Tromey <tromey at redhat dot com>]

I'd like to ping this patch of Daniel's:

http://sourceware.org/ml/gdb-patches/2007-10/msg00510.html

I didn't see any response to the content of this patch.

I would like to put this in as a prerequisite for the Python
pretty-printing support.  Without this, it is difficult to manipulate
some types by name, e.g.:

http://sourceware.org/ml/archer/2008-q4/msg00219.html

We've been using this on the Python branch, and a couple others, for a
while without ill effects; though Jan did find a bug and supplied this
additional fix:

http://sourceware.org/ml/archer/2009-q1/msg00383.html

If there are no comments I will check this in.

Tom