Additionally, improve handling of Primary_last_was_super. Previously,
it was cleared to 0, which made sense if the ship starts with only
lasers. Now that the ship can start with other weapons, clearing
Primary_last_was_super to 0 may override a player's choice. Preserve
player's last-was-super choice when the grant gives both the base and
super forms of a weapon.
Requested-by: Mako88 <https://github.com/dxx-rebirth/dxx-rebirth/issues/140> [for the Primary_weapon part]
35cd1261df