Keep the same active layer and frame when switching back a timeline. - Add functions to remember frame and layer for timeline at domview. - Recall active frame and layer when calling switch_component() and switch_timeline().

# -*- 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