[WFLY-1877] : Make KeepAliveTimeAttributeDefinition deal with both a sim...

...ple long and a complex attribute.

Updating the ejb3, connector and batch subsystem to threads 2.0 .
Jira: https://issues.jboss.org/browse/WFLY-1877
This depends on wildfly-core PR: https://github.com/wildfly/wildfly-core/pull/64