Fixed bug in signpost handling code

Two of the coordinates were flipped in markers.js
Also, overviewer.dat is now removed with -d

chunk.py

@@ -626,8 +626,8 @@ class ChunkRenderer(object):
                 # coordinates to global world coordinates
                 newPOI = dict(type="sign",
                                 x= entity['x'],
-                                y= entity['z'],
-                                z= entity['y'],
+                                y= entity['y'],
+                                z= entity['z'],
                                 msg="%s\n%s\n%s\n%s" %
                                    (entity['Text1'], entity['Text2'], entity['Text3'], entity['Text4']),
                                 chunk= (self.chunkX, self.chunkY),

gmap.py

@@ -145,6 +145,12 @@ def delete_all(worlddir, tiledir):
                     logging.info("Deleting {0}".format(filepath))
                     os.unlink(filepath)
 
+    # delete the overviewer.dat persistant data file
+    datfile = os.path.join(worlddir,"overviewer.dat")
+    if os.path.exists(datfile):
+        os.unlink(datfile)
+        logging.info("Deleting {0}".format(datfile))
+
 def list_worlds():
     "Prints out a brief summary of saves found in the default directory"
     print