…dged_infill_margin:

 * get ps2.9 partial & disabled option.
 * restore 2.5 process_external_surfaces before discover_vertical_shells
 * 2.7 and 2.9 option are still with discover_vertical_shells before process_external_surfaces, but this break the anchor margins.
 * the solid_over_perimeters can affect the anchor where the perimeter are well above -> unwanted.
 * this is still wip, there is at least a week of investigation to understand & document how it work.

 * now z_offset is added by the gcode writer (and the wieptowerwriter).
 * all computation is done on the un-offseted z
 * only the "position" placeholder contains the z offset.
 * moved some placeholder into the placeholder_parser_process, as they are used everywhere.

…iant

…iant

outdated 'fuse' package break dependencies and uninstalls cinnamon and potentially other DEs