this is part of an upgrade process to the latest version of Dear ImGui it will take a while as I am stepping through individual versions due to the heavy modifications we've made for Furnace
commit f8704cd085c4347f835c21dc12a3951924143872 with Furnace patches
commit 8fd0a041355e3cfc6556bbe1e00f262d9a897946 with Furnace patches
allows for local modification which is necessary see #442