Compile fixes for xfs

[Keith Packard]

Here's a set of patches which gets xfs compiling, and compiling
without warnings. The last two patches relate to another patch series
that I sent for libxtrans, so you probably want to look at these two
sets together.

General warning fixes and API breakage fixes for libXfont

 [PATCH xfs 1/3] Warning fixes.

Fixes related to libxtrans changes. The last patch should probably
have a check for the version of libxtrans that is in use; it's an
error to pass a const actual to a non-const formal.

 [PATCH xfs 2/3] Define VErrorF and then try to get libxtrans to use
 [PATCH xfs 3/3] Pass a const char * port to TRANS(ReopenCOTSServer).

-keith