(svn r17214) -Add [NoAI]: GetAPIVersion() as optional function in info.nut. Return "0.7" to get an api compatible (as much as possible) with the 0.7 api or "0.8" to get the latest api.

-Change [NoAI]: move all deprecated functions to a separate squirrel script that is only loaded if an AI requests an old API version.

src/ai/api/ai_sign.hpp

@@ -28,14 +28,6 @@ public:
 		ERR_SIGN_TOO_MANY_SIGNS,             // [STR_ERROR_TOO_MANY_SIGNS]
 	};
 
-	/**
-	 * Gets the maximum sign index; there are no valid signs with a higher index.
-	 * @deprecated This function is deprecated and might be removed in future versions of the API. Use AISignList() instead.
-	 * @return The maximum sign index.
-	 * @post Return value is always non-negative.
-	 */
-	static SignID GetMaxSignID();
-
 	/**
 	 * Checks whether the given sign index is valid.
 	 * @param sign_id The index to check.