[Quest API] Add IsRaining() and IsSnowing() to Perl/Lua.

- Add quest::IsRaining() to Perl.
- Add quest::IsSnowing() to Perl.
- Add eq.is_raining() to Lua.
- Add eq.is_snowing() to Lua.

This will allow server operators to tell if a zone is currently raining, snowing, or neither.

zone/questmgr.h

@@ -340,6 +340,8 @@ public:
 	int GetRecipeMadeCount(uint32 recipe_id);
 	std::string GetRecipeName(uint32 recipe_id);
 	bool HasRecipeLearned(uint32 recipe_id);
+	bool IsRaining();
+	bool IsSnowing();
 
 	Client *GetInitiator() const;
 	NPC *GetNPC() const;