add local version of BTreeSet
pass the simple test
pass load and save test
fix the union and intersect test
Merge remote-tracking branch 'github/genomix/fullstack_genomix' into jianfeng/node-store-in-hdfs
update BTree API
add ExternalableTreeSet
add test for ExternalSet
wbiesing/ray-genomix-refactor
not compilable ? fix the node
change all the usage of ReadHeadSet
record any Counters from the pregelix job as part of STATS
add cmdline option `-runAllStats` to insert STATS between all jobs
temporary test
add test for union update of vkmerlist
fix bug of unionUpdate() of vkmerList
use assert in test case for testUnionUpdate
complicated test
remove ray dependence on old scaffolding aggregator
bugfix for P4: newEdge unused and outgoingMsg not properly reset for updates