Like with the compute RPC API, we're unlikely to still work well with
RPC client using older 1.x version because of DB schema changes.
In that case, we may as well remove 1.x support in Folsom and rip out
the potentially buggy backwards compat code. This should also make
backporting fixes from Grizzly easier.
Deployers following trunk can upgrade all their nodes to use the version
2.0 API before deploying this commit.
Change-Id: Iee099751bda9637da5e134357d28e89d5fba9895