#92 Delete 0 byte size resource forks

[Ralph Böhme]

There's no real difference between a resource fork not being present and being empty, so we can simply delete it if it's closed and empty.

[Ralph Böhme]

Delivered in Change-Id ef5f88f5f2cefa75cf20d0ee447b4e20579a2f12 for 3.1.3.