[Mono-winforms-list] TreeView: Handling of Mouse-Events and two minor bugfixes

[Valentin Sawadski]

Hello all,

following Everaldos request I've tried to fix some of the smaller bugs
of the TreeView.

So far, I managed to fix 81779 and 81839 (both patches are in bugzilla
for review).

But while working on 81739 I've noticed that MouseEvents in TreeViews
are handled strangely because the appropriate OnMouseXXX methods are
only overridden by parts of the mouse event, the rest subscribes to his
own MouseXXX-Events instead.

Is there any reason why this has been implemented this way and would it
make sense to alter all the events to override the OnMouseXX methods
(for more performance and more readable code)? And btw is someone
already working at this bug so that I should leave it alone?

Kind Regards,
Valentin S.