* changed transport speed in session and slaves from float to double

* added some comments


git-svn-id: svn://localhost/ardour2/branches/3.0@4394 d708f5d6-7413-0410-9779-e7cbd77b26cf

libs/surfaces/control_protocol/basic_ui.cc

@@ -184,12 +184,12 @@ BasicUI::next_marker ()
 }
 
 void
-BasicUI::set_transport_speed (float speed)
+BasicUI::set_transport_speed (double speed)
 {
 	session->request_transport_speed (speed);
 }
 
-float
+double
 BasicUI::get_transport_speed ()
 {
 	return session->transport_speed ();