remove the inplace flags. It is the opt that should add them, but opt in this file only move the computation to the gpu. They don't make them inplace.

finish fix gh-842

This only remove warning from DebugMode.

fix first part of gh-842

initialize the destroy map to empty

No NEWS.txt. This is related to change in the trunk and happen only when we try to use Theano without g++.

Support for undefined gradients

Mixed3

(needed to express that gradient with respect to x is undefined
if x is allowed to be None)

added a new kind of bad grad, undefined grad

We don't want to do it at import time.

renamed FunctionGraph.extend to FunctionGraph.attach_feature

made extend call attach_feature