Fix #544. Add a way to force remove a node

This patch adds an endpoint as well as interfaces to RaftServer and
ClusterConfiguration to make it possible to forcibly remove a node from
the cluster. The way it works is similar to changing the connection
string. An InfluxJoinCommand command is created applied to local node as
well as other nodes in the cluster directly, then the command runs
through raft to make sure the change is permanent.
add a test for #578
remove a print statement
update the changelog
Fix #559. Add a test to demonstrate that this isn't a bug
update the name of the package
Merge pull request #544 from influxdb/fix-544-force-remove-node

There should be a way to force a node to leave the cluster
Update CHANGELOG.md
err could be EOF according to the docs
Close #591. Add support for multiple UDP + JSON input plugins

Support comes by way of [[input_plugins.udp_servers]] in config.
A single port will map to a single database.
More idiomatic and DRY
Remove some unused fields and fix the test
Fix #579. Reject writes to nonexistent databases
Close #566. Add some timing data to the logs
Fix some tests broken by #579
Fix #597. Force compaction after deleting data
Close #600. Fix #599. Report os, arch, and raftName once per day.
Update the changelog
simplify the code since we don't need the quit channel
fix the release script to use crosstools