added ones_like, zeros_like, misc unittests

gof/lib.py

@@ -205,11 +205,15 @@ class PythonOp(Op):
         for input in self.inputs:
             if input not in exc:
                 self.check_input(input)
+        if 0:
+            #J- why is this try catch here? Leftover debug?
             try:
                 results = self._impl()
             except Exception, e:
                 print "Error in %s: %s" % (self, e)
                 raise
+        else:
+            results = self._impl()
         if self.nout == 1:
             self.out.set_value(results)
         else:

grad.py

@@ -331,4 +331,3 @@ class _testCase (unittest.TestCase):
 
 if __name__ == '__main__':
     unittest.main()
-