add -b BRANCH and -d TESTDIR args to runner_setup.sh, args passed from the top level runner*sh scripts. (and in jenkins as jenkins downstream parameters)

move syn_datasets under sandbox (SYNDATASETS_DIR is used in all tests, so invisible except for parity.pl was hardwired, now gets datasetsDir param..and a couple of tests had some hardwired syn_datasets..fixed)
Merge branch 'master' of github.com:0xdata/h2o