Extends lua's SD API to add a remove_node method, similar for remove_item

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>
fix gui/skins2: ft2_bitmap.cpp write after allocated block

this fixes trac #10134

Signed-off-by: Erwan Tulou <erwan10@videolan.org>
Merge remote-tracking branch: upstream/master