Added file check to icon changing.

pe.py

@@ -1222,10 +1222,14 @@ class PEFile(Printable):
         of the file, but that did not work. Comments were left as history
         to what I attempted.
         """
+        icon_path = os.path.expanduser(icon_path)
 
         if pm is None:
             raise Exception('PythonMagick is required to run this function.')
 
+        if not os.path.exists(icon_path):
+            raise Exception('Icon {} does not exist'.format(icon_path))
+
         resource_section = self.sections['.rsrc']
 
         g_icon_dir = self.get_directory_by_type(ResourceTypes.Group_Icon)