Update comment after code review.

Fix test and update NEWS.txt

We explicitly use and -inf in the graph, so DebugMode shouldn't complain about this.

The problem was caused by the name conflict between the scan submodule and the scan function.

This reverts commit 7fa448b8.

make filter for CudaNdarray check for stride == 0 for dim == 1.

Conflicts:
	theano/compile/function.py
	theano/compile/pfunc.py
	theano/gof/fg.py
	theano/gof/type.py