Added -h instead of -?. And upon -h and --help, write usave to stdout
instead of stdin, and return 0 instead of 1.
-? still works like before as that's what getopt returns upon unknown
arguments.
A private FcObjectGetSet() is implemented that provides an
FcObjectSet of all registered elements. FcFontSetList() is
then modified to use the object set from FcObjectGetSet() if
provided object-set is NULL.
Alternatively FcObjectGetSet() can be made public. In that
case fc-list can use that as a base if --verbose is included,
and also add any elements provided by the user (though that has
no effect, as all elements from the cache are already registered).
Currently fc-list ignores user-provided elements if --verbose
is specified.