moved off deprecated TagClient -> TagApi

any ec2-clone who's apiVersion is set to at least 2010-08-31 will now have node tags and metadata applied by the end of the createNodesInGroup call.  details are logged to the `jclouds.compute` logger, including trace level info validating application of tags.

The logic replaces old, flakey code which tried to copy metadata from spot requests to instances (flakey as async calls were never checked for success and could not be applied).

As a side-effect, the base RunningInstance class in apis/ec2 now has tags.

cc @otfrom @hugoduncan @anshul1886