Upgrades Spring Data GemFire 1.5 to GemFire 7.5.
Final updates to SDG's build.gradle script to resolve GemFire 7.5 build artifact snapshots in order to build SDG with support for GemFire 7.5 features and functionality.
Implements JIRA feature request SGF-227 adding support for GemFire 8.0's auto-reconnect functionality on forced disconnects.
Implements JIRA feature request SGF-226 enabling Spring Data GemFire to retrieve the shared, persistent cluster configuration from a GemFire 8 Locator Shared Configuration service when the SDG configured peer cache member joins the cluster.
Additional changes for JIRA feature request SGF-226 supporting GemFire's new Cluster-based Configuration Service.  Renamed the CacheUsingSharedConfigurationIntegrationTest class to CacheClusterConfigurationIntegrationTest and added an additional test case to assert the default, non-use of cluster configuration behavior.  Renamed GemFire System properties references for enabling/disabling Cluster Config based revision r48252 in GemFire 8.
Additional changes for SGF-226 supporting cluster-based configuration in GemFire 8 based on latest changes to the shared, persistent cluster configuration service in preparation for the 8.0 release.  The recent changes in SDG for the shared, persistent cluster-based configuration feature are based on GemFire RC build number r48398.
Upgraded SDG to GemFire 8.0.0 GA.