Fix bugs of inserting/removing frames. - tracking layer.scenes when add/remove scene nodes. - fix buggy add_frame()/rm_frame() of frameline. - change ID of nodes before inserting when copy nodes from another group.

# -*- indent-tabs-mode: t; tab-width: 8; c-basic-offset: 4; -*-
# vim: sw=4:ts=8:sts=4
m4datadir = $(datadir)/mb
dist_m4data_DATA = foreach.m4 mb_c_header.m4 mb_c_source.m4
dist_bin_SCRIPTS = svg2code.py