Let SendToUnsynced send tables

[sprunk]

Right now it only accepts simple types. The caveats are that

• simple types can be passed just like that, but for tables the implementation will need to make a copy so that unsynced can't edit it
• functions can't be passed at all (because they can be closures and/or sync-affecting C functions). Userdata is probably also unsafe to pass. So tables will need to be stripped to just simple types plus tables.

Both of those are done for the SYNCED. table so perhaps look there for inspiration.

spring/rts/Lua/LuaHandleSynced.cpp

Lines 1967 to 1972 in 04215da

	static const int supportedTypes =
	(1 << LUA_TNIL)
	| (1 << LUA_TBOOLEAN)
	| (1 << LUA_TNUMBER)
	| (1 << LUA_TSTRING)
	;