Rename IOFSwitch.getRole() to getHARole(), remove isActive()

src/main/java/net/floodlightcontroller/core/IOFSwitch.java

...va/net/floodlightcontroller/core/internal/Controller.java

.../net/floodlightcontroller/core/internal/OFSwitchImpl.java

...net/floodlightcontroller/core/web/SwitchRoleResource.java

...et/floodlightcontroller/core/internal/ControllerTest.java

.../floodlightcontroller/util/OFMessageDamperMockSwitch.java