Release notes for 402

Improve clarity of Lua error messages, for example foo.bar now fails with attempt to index nil with 'bar' if foo is nil.

X/Y/Z accessors for Vector2, Vector3 and CFrame are now ~30% faster.

Brackets and quotes are no longer automatically closed in comments or strings.

Fixed a crash in mass/inertia calculation code when welding chains of ~4K parts. Still recommend against welding things that way if it's not literally a four thousand block stack. Do whatever is natural for the construction, but everything in the assembly welded to one central part is definitely the best case for performance.