Not useful anymore, it can only fail if the GameSave passed in is nullptr, which this commit guards against.
Also make Simulation::Load and Simulation::Save take block-oriented positions and rects.
Saving blockair/blockairh is nice because RecalculateBlockAirMaps uses the sim rng, which means the sim rng would get advanced in Simulation::Load. Also rename RecalculateBlockAirMaps to ApproximateBlockAirMaps because that's what it is, an approximation, and it's needed only if there are no block air maps in the save.
Simulation::frameCount keeps track of frames elapsed since the beginning of the simulation, zeroed at clear_sim. It overflows when it reaches the 64-bit limit, which means anything that depends on it should either handle this, or not fail catastrophically. sandcolour (the only thing that depends on it as of now) is a good example of the latter: sandcolour has a periodicity of 360 frames, which means that there is one sandcolour period that is cut short by the overflow. This is not "handled" (the period is cut short, which is detectable by users) but is not catastrophic either (it's not a big deal, and it won't ever happen unless someone hacks the save).
Also restrict saves with determinism data to 98.0.
A bug existed before where certain events would not update Engine's lastTick. If the sim was lagging hard, then this could cause "script is not responding" errors to appear in unintentional situations.
The starting execution time is tracked in LuaScriptInterface instead now, and set in tpt_lua_pcall
Also replace a few rename calls with RenameFile calls. Old code doesn't expect rename to overwrite existing files without question, when it in fact can.
We can't rely on atexit, handlers registered with it are in a hard to establish ordering relationship with destructors of static and thread-local objects.
... while retaining all the functionality of stamps.def.
Also fix stamp names encoding only 32 bits of the timestamp, migrate from stamps.def to stamps.json if the latter doesn't exist, delete both on migration to the shared data directory, rescan stamps at startup, and make rescanning a painless process in general by removing invalid entries and adding missing entires at the beginning of the list.
Request ownership is no longer flaky. Requests are now owned by the code that makes requests, and Requests and the RequestManager co-own RequestHandles. RequestManager disowns a RequestHandle if it's done with it or if Request code reports that it's no longer needed.
All libcurl code has been moved to RequestManager. This is nice because once NOHTTP is removed, we can add any number of RequestManager implementations, for example one for Android.
Client outliving RequestManager is still a problem, this will have to be addressed later.
More precisely, refactor the code responsible for routing these GameController events to the Lua side. The issue with the previous solution was it relied on preprocessor macros to switch between Lua-ful and Lua-less builds.
