[Feature] Adding game save/load callbacks for lua scripting.

[Neloreck]

Adding optional lua callbacks to allow creation of custom saves.
Following same pattern as CoC/anomaly mods. Having marshal library without these callbacks does not make complete sense because NetPacket has size limitations and requires strict data ordering.

Changes:

• Added on_before_game_save lua callback
• Added on_game_save lua callback
• Added on_before_game_load lua callback
• Added on_game_load lua callback

[Xottab-DUTY]

Sorry! This feature will be merged as a part of the Call of Chernobyl code merge, but with CoC/Anomaly matching callback names.

[Neloreck]

Is there any WIP branch / fork?

[Xottab-DUTY]

Is there any WIP branch / fork?

Not yet, I screwed some changes and discarded the branch (but saved the already finished work luckily) yesterday. I will start again somewhat soon. There's not much changes really.

[Neloreck]

Sounds good. Do we expect CoC to work out of box with OXR engine + their gamedata?

[Xottab-DUTY]

Sounds good. Do we expect CoC to work out of box with OXR engine + their gamedata?

Yes, but it's the same as for other mods – there might be errors in scripts which are ok for luabind used in vanilla engine (and CoC engine), but our luabind may not tolerate them.

1. Hopefully, there's no to little number of these errors.
2. I'd like to make our luabind behave the same as vanilla one, to make our engine 99-100% compatible with mods, but it requires some research on behaviour differences.

[Xottab-DUTY]

CoC support can be tracked in #1529.

[Neloreck]

@Xottab-DUTY
Should I just integrate it from https://github.com/revolucas/CoC-Xray/blob/master/src/xrGame/alife_storage_manager.cpp ?