[2.3.x] Incremental changes for https://java.net/jira/browse/GRIZZLY-1546 (Ref GRIZZLY-1345. Generalize the graceful shutdown to be a feature of the core transport vs specific to http-server).
 - Create unique identifier for shutdown threads based on transport name and hashcode of the transport being shutdown.
[2.3.x] Incremental changes for https://java.net/jira/browse/GRIZZLY-1546 (Ref GRIZZLY-1345. Generalize the graceful shutdown to be a feature of the core transport vs specific to http-server).
 - Minor tweak to previous commit.
[2.3.x] Incremental changes for https://java.net/jira/browse/GRIZZLY-1546 (Ref GRIZZLY-1345. Generalize the graceful shutdown to be a feature of the core transport vs specific to http-server).
 - Remove sout.
[2.3.x] + fix findbugs issues
[2.3.x] + fix findbugs issues