Add tile indicators plugin

Add tile indicators plugin, that will currently highlight the tile
player is walking to. It is disabled by default, and have configurable
highlighting color.

Signed-off-by: Tomas Slusny <slusnucky@gmail.com>

runescape-api/src/main/java/net/runelite/rs/api/RSClient.java

@@ -332,4 +332,10 @@ public interface RSClient extends RSGameEngine, Client
 	@Construct
 	@Override
 	RSIndexedSprite createIndexedSprite();
+
+	@Import("destinationX")
+	int getDestinationX();
+
+	@Import("destinationY")
+	int getDestinationY();
 }