Update test server node generation for riak 1.4

In addition to making the test server work with riak 1.4; this PR makes the following high level changes:

* Simplify the generation by coping everything except the data directory.
* Remove support for a symlinked basedir.
* Depend less on the control script.
* Add support for the env script.
* Move protobuf config to riak_api for 1.4 only
* Make backward compatible with riak 1.3.