changed the argument order for MutableGraph to be consistent

with the other functions.
Also added the remove_edge(e, g) and remove_edge(iter, g) functions.


[SVN r7856]

libs/graph

@@ -1 +1 @@
-Subproject commit e80dc97c43b83ec94ee92077044beb09f6507dcb
+Subproject commit 9245287c650370d70a142a6f749cd57314058d9b