Fix opt error/skip in scan, add Shape.c_code()

Fix import of compat module in python 3.3.0

In python 3.?, dict order are random, so object attribute are also random!

added scipy.stats.chi2.sf op

Finish chi2 tests and GPU code.

they work on the GPU.

Fix test p33

Should solve travis-ci tests in this PR.

This enable elemwise opt with flatten in the middle.
This can also enable more elemwise fusion that got split by flatten.

is the variable name used.

I lost 1h before undersanding it isn't the name used in the optdb.

Also test that we can disable inplace and fusion opt with MonitorMode.