fCurrentLayer was used to determine to which layer a new one would be
added to, but BView::AddChild() would only set this correctly for the
current view, ie. all children of the new child were added to the
wrong layer in the app_server.
Now, AS_LAYER_CREATE sends the parent's token to the server, and the
server relies on this to build the layer hierarchy.
All of a sudden a lot of hidden views are visible now. I noticed the
bug while refactoring the task manager, but a lot of apps were affected.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@13164 a95241bf-73f2-0310-859d-f6bbb57e9c96