The statistics counters "files in cache" and "cache size" now only include
object files. It's not worth the effort to keep track of the .manifest, .d and
.stderr files since the cache size is dominated by the object files, and it's
unlikely that anyone is bothered by du(1) having a different opinion (which
also was the case before anyway). Consequently, the "max file" and "max cache
size" settings now specify thresholds for object files count and size.
