Changed graph traversal routines in scan_utils.py to not visit any subgraph more than once
Improved comment on the new visited set in scan_utils.py traversal routines.
Fixed crash for unimplemented elemwise gradient

This bug was reported by Michael McNeil Forbes on the mailing-list.
PEP8
removing a bug
add unit test
Fix bug when unpickling previous versions of CAReduce
Made size argument mandatory in normal(..)

Having it default to None suggests it is optional, which is not true (it
will crash when using None).
Fix check for 0 in values
Merge pull request #1336 from bbudescu/master

windows port
Merge pull request #1334 from delallea/minor2

Made size argument mandatory in normal(..)
Call parent __setstate__, so self.ufunc is correctly set.

Thanks @delallea for finding it.
Merge pull request #1 from lamblin/fix_elemwise_perform

Fix check for 0 in values
Merge pull request #1325 from f0k/fix-scanutils-traverse

scan_utils.py: Make traversal routines remember visited nodes
Improved test
Merge pull request #1328 from SinaHonari/myBranch

removing a bug
Merge pull request #1326 from delallea/notimplemented_elemwise_grad

 Fixed crash for unimplemented elemwise gradient
Fix error in previous commit
Merge pull request #1332 from lamblin/fix_careduce_unpickling

Fix bug when unpickling previous versions of CAReduce
fix for get_constant_value