Xprt links libfb, which now uses pixman. Update configure.ac to
require module $PIXMAN for XPRINT.
Also, use $(top_builddir) to reference libfb.la and other local
libraries, rather than using the relative reference ../..
Now, fbcmap_mi.c contains the fb functions which just wrap mi functions.
Previously, these were in fbcmap.c and compiled when XFree86Server was defined.
Now, clients of fbcmap should either use fbcmap.c or fbcmap_mi.c and not worry
about setting the XFree86Server symbol.
Get rid of almost all uses of these definitions. They're still defined for
delinquent out-of-tree drivers, and also for the Mesa build. As well as
for miinitext.c. But largely gone.
