Revert "gcancellable: allow g_cancellable_disconnect from "cancelled" handler on same thread"

This reverts commits 83605e2d0a7b0d39987715cfd046f7b8ef6de94e and
140fa7ee4669adb3827e3ddea5be57f51ee7af3e.
More gio-du win32 fixes

Don't free the utf8 filename before the async function completes.

also, gitignore
gio docs: add some missing functions
fix up refcount/properties test case

Recent changes to the properties testcase made invalid use of the GArray
free function.  This free function takes a pointer to the item to be
freed, not the item itself.  Since that item was a pointer to a GObject,
g_object_unref() was getting a GObject**, rather than a GObject*.

The use of GArray in this testcase is pretty questionable in the first
place, so just use C arrays instead.
GLib 2.38.0