Termination protection enhancement

I'm not sure if we want to merge this just yet, but I opened this pull req for discussion.

Added support for toggling termination protection using the botocore lib which is now [0.5.1 in Pypi](http://pypi.python.org/pypi/botocore/0.5.1).

Also wrapped the core libcloudfuncs.destroy() method to gracefully handle the exception raised in libcloud when termination protection is switched on for a node.