Adds baremetal support to GCE fence agent and API call retries (#355)

• Adds baremetal support to GCE fence agent and API call retries

Adding an additional --baremetalsolution command line argument to support GCE baremetal API changes
Enabling FENCE_GCE_URI_REPLACEMENTS environment variable for generic gogoleapi URI replacement
Adding --retries, --retrysleep, --apitimeout to fine tune the API call timeout, retries, and retry sleep

• Fixing the xml for the new baremetal options