[GEOS-6755] GSIP 119 - WPS clustering of asynchronous requests - architecture refactor to allow pluggable status sharing
[GEOS-6755] GSIP 119 - Hazelcast based status store
[GEOS-6755] GSIP 119 - Adding heartbeat so that long procesess not reporting progress won't have their resources expired by mistake
Merge pull request #810 from aaime/wps_cluster_hz

WPS clustering - with Hazelcast based store
Exposing style generator from importer
Fixing nightly build compile/build failures in wps-download
[GEOS-6770] Allow flow controllers access to the current Operation
Have the artifact store work with a NIO lock directory inside GEOSERVER_DATA_DIR/tmp