* src/filetree.cc (FileTree::expand_and_select): Replace the
calls to TreeSelection::select() and TreeView::scroll_to_row()
by a single TreeView::set_cursor() call.
(FileTree::find_files): After the tree has been filled in, the
first call to expand_and_select() doesn't always scroll to the
selected row (no matter if set_cursor() or scroll_to_row() is
used there).  Explicitely scroll to the first row after filling
the tree to work around this problem.