Write the VERSION file in rtdev-current.sh.

This also ports over some formatting niceties from riak_test.
Allow regular devrels in riak_test by using a wildcard path.

Previously, the path to the riak_cs/ebin had to be exact. This allows
version numbers to be appended to the first part.
Update riak_test/README.md with newer instructions and examples

* Remove the warning about `stagedevrel`, as a wildcard is now used
  instead of a static path.
* Add `rt_project` key to the configuration example so that giddyup
  reporting will work.
* Remove "deps" from `rt_deps` key because it is already added by
  `riak_test`.
* Add `test_paths` key for automatically slurping in riak_cs' tests.
* Reflow some paragraphs.
* Since the `test_paths` key is added, the `-d` option is no longer
  necessary except when wanting to run all tests.
Merge pull request #618 from basho/feature/sdc-riak-test-updates

Updates for working with riak_test