SGE timezone handling
Got rid of remote_tzname
add remote_tzinfo kwarg to SGEStats and default to UTC

This prevents the existing SGEStats tests from failing and makes it
easier to set an alternate timezone from the load balancer.
keep SGEStats's tzinfo up-to-date with master node

Converted SGELoadBalancer.stat attribute to a caching property that, on
intial creation, calls SGELoadBalancer.get_remote_time and sets the
proper remote_tzinfo attribute on the stats object. Updated
SGELoadBalancer.get_remote_time to update the cached SGEStats'
remote_tzinfo (assuming it exists).
Merge branch 'fix-sge-tzinfo' into develop

closes gh-385