Fix #71 : Report disk space usage on Partition Servers
Add logging to filesystem root detection
Stop trusting Java to detect the filesystem roots.
Move update filesystem statistics thread to PartitionServer
Fix compilation
Fix filesystem statistics reporting
Change frequency of filesystem statistics update to 2min
Minor UI improvements
Minor UI improvements
Minor UI improvement
Minor UI improvement
Minor UI improvement
Use a HashSet instead of a TreeSet to maintain set of data location change
listeners.
Add logging to PartitionServer
When not sync connected, do nothing in HankWatcher
Avoid creating useless objects in UpdateManager
Proactively serve data of an updated host, even if its ring hasn't finished
updating as a whole.
Skip WatchedNode notifications when the actual node is unchanged, as opposed
to when the value hasn't changed.
When stopping processes, use kill -9
Minor UI improvement.