T5 very simple test for Varz abstract class (because of one defined method)
T5 cleanup
some nulls changed to Scala Options
T5 one more test for Varz
tests for HTTP Response codes ; some little changes in code
T5 added double quotes in JSON
T5 tested JSON with some varzs
T5 tested JSON with zero and one varz + other minor changes
changed server life time (in usage example)
Merge branch 'T5' into dev