Special characters are not escaped

[deadok22]

The library does not escape special characters in metric names and tags, which can result in malformed packets and unexpected tags being sent over the wire.

E.g. this:

        final NonBlockingStatsDClient c = new NonBlockingStatsDClient("", "localhost", 8125);
        c.gauge("check:11|g#this:out", 42, "tag1,tag2,tag3");
        c.close();

Results in:

$ nc -u -l localhost 8125
check:11|g#this:out:42|g|#tag1,tag2,tag3