#ifdef out old cache stuff, replace with first version of new mmapping
cache. Add *Read and *Write procedures which mmap in and write out the
fontconfig data structures to disk. Currently, create cache in /tmp,
with different sections for each architecture (as returned by uname's
.machine field. Run the fc-cache binary to create a new cache file;
fontconfig then uses this cache file on subsequent runs, saving lots of
memory. Also fixes a few bugs and leaks.