Update the ChangeLog date for v0.16rc1
Allow overwriting the name of the kvm executable

Export a KVM variable. This can be used to overwrite the executable for
the kvm command.
pithcat: Use ModularBackend class attribute

ModularBackend introduced a class attribute that denotes
the class version. Since class version 1, ModularBackend
supports Archipelago as it's main storage backend. Use the
new class attribute to instantiate ModularBackend class
appropriately.