Due to rounding and conversion approximations, it was possible for FRED to think the position and/or angle was modified when no such modification had occurred. This could result in erroneous updates. In the case of angles this could result in a group of ships being assigned the wrong orientation.
Follow-up to #2614.
This could happen if the user enabled "Point to" and selected "Object"
without having an object selected. This can only happen when there is
only one object in the mission so it's only a minor bug but still
something worth fixing.
This introduces a new mechanism for handling bit flags. Instead of using an int (or two, or three) to write bits into, this uses the std::bitset in a wrapper class that accepts an enum class as input. This means that certain classes of errors we've had a few of in the engine, where a coder used the wrong set of flags or checked them against the wrong variable (SF_STEALTH vs SIF_STEALTH, for example) can now be detected at a compiler level rather than not at all.
Goober5000