Update Riak CS test runner for Riak 2.0

Most of this file has already been copy-pasted from rtdev.erl. We'd like
to eventually fix that, but in the interest of getting the tests
running, this commit just brings it back up to date, using the same
technique.
Setup test for CRDTs upgrades, currently only 1.4 counters
add ensemble_remove_node
Allow cover_modules and cover_apps to be per test module

Instead of one giant list in the config file, use module attributes to
indicate which apps/modules a particular test is intended to test.

This helps reduce noise when doing a complete cover run because lots of
the tests don't test things like riak_control or riak_repl.
./riak_test -b backend now works with rtcloud
Fix an error that can lead to failure of tests using replication2_pg

Fix an error that can lead to failure of tests using
replication2_pg:test_pg_proxy test case. A protocol buffers connection
is established to a node in the "B" cluster, the leader node from that
cluster is shut down, and then that protocol buffers connection is
used to exercise proxy_get. If the connection was established to the
former leader and that is subsequently shut down it can cause the test
to stall and eventually fail. This changes that test to establish a
new connection to a node remaining in the "B" cluster to use for the
proxy_get and prevents the test from stalling.
Wait for transfers to complete in replication2_pg:test_pg_proxy

Wait for transfers to complete in
replication2_pg:test_pg_proxy. Replication tests that test the n_val=1
request option can fail with insufficient_vnodes errors if the cluster
setup does not include waiting for transfers to complete. Change the
test_pg_proxy test case to wait until transfers complete on the "A"
and "B" clusters before proceeding.
Update README about cover changes
Test cluster state and root ensemble members after node leaving in ensemble_remove_node
remove outdated print statements
Refactor test to assert downgrade.

When performing the test of object reformatting through replication,
assert that if we happen to downgrade the format we can still read the
keys which have been replicated.
Merge pull request #582 from basho/bugfix/replication2-nval1-request-failure

Wait for transfers to complete in replication2_pg:test_pg_proxy
Merge pull request #580 from basho/bugfix/jd/rtssh-set-backend

./riak_test -b backend now works with rtcloud
Add basic moving target stats test.

Use this as a platform to start testing reports of missing stats from
replication.
Change rpc handling in rt module to handle badrpc returns

Change how the return from some rpc calls is handled in the rt module
in order to avoid spurious or misleading test failures.
Fix refactoring bug in wait_until_all_members function
s/badprc/badrpc
Merge branch 'bugfix/rt-rpc-fixes'
If the test does not define coverage modules/apps use what is in the config

To help in the migration to annotated riak_tests, allow the global cover
lists in the riak_test config to be used as a fallback for tests with
no annotations.
Safer mod_src, damm NIFs