Add string.rsplit: until the maxsplit parameter is implemented it can use string.split

src/runtime/str.cpp

@@ -422,6 +422,7 @@ void setupStr() {
     CLFunction *strSplit = boxRTFunction((void*)strSplit1, LIST, 1, false);
     addRTFunction(strSplit, (void*)strSplit2, LIST, 2, false);
     str_cls->giveAttr("split", new BoxedFunction(strSplit));
+    str_cls->giveAttr("rsplit", str_cls->peekattr("split"));
 
     CLFunction *__new__ = boxRTFunction((void*)strNew1, NULL, 1, false);
     addRTFunction(__new__, (void*)strNew2, NULL, 2, false);

test/tests/str_functions.py

@@ -10,3 +10,5 @@ print "  test  ".split()
 print "  test  ".split(' ')
 print "  test  ".split(None)
 print "1<>2<>3".split('<>')
+print "  test  ".rsplit()
+print "1<>2<>3".rsplit('<>')