changing "StreamEvent" to "stream-event"

[Mark Polesky]

I noticed this thread from two years ago:
http://lists.gnu.org/archive/html/lilypond-devel/2007-07/msg00020.html

Apparently, StreamEvent should be renamed stream-event. I'm happy to do
that, but is it really as simple as changing these 2 lines (lines 12-13)
in scm/define-event-classes.scm? Or is there a C++ file somewhere that
also needs to be changed (or something else that I wouldn't know about)?

- Mark

11 (define event-classes
12   '((() . (StreamEvent))
13     (StreamEvent .
14                  (RemoveContext ChangeParent Override Revert UnsetProperty
15                                 SetProperty music-event OldMusicEvent 
CreateContext Prepare
16                                 OneTimeStep Finish))