Add SmartOS detection and mount plugins
Dummy communicator runs :test correctly
Add unit tests for smartos compatibility
Smartos guest capabilities includes rsync_pre
Resolve confusion around SmartOS rsync_pre

rsync should *always* be pre-installed in SmartOS (global and local zones), as
it's part of the kernel. Previous commits incorrectly attributed #rsync_install
to running rsync, rather than to installing the rsync command.
Merge pull request #3102 from sax/smartos

guests/smartos