Do not test div on denominator too close to 0.

The numeric estimation of the gradient was sometimes quite off.

Remove new bugged version of GpuSum commited in a pep8 commits.

Crash fix gpu reshape

Blas

Remove AddSSData Optimization

Fix elusive output-corruption bug in Scan.

The problem was that when copying a part of an array onto an overlapping
part of the same array, sometimes elements were overwritten before being
copied, leading to silent data corruption.

Import 'any' for python 2.4

Fixed crash when cuda is not available

This crash was introduced recently by ccb01355

Alloc

Also, don't print {} is there is no param to print. There is many scalar op like switch, LE, GT, ... that don't have a specified name.

Checks for preallocated output memory, take 2

Added theano.clone in the doc.

That way, we can more easily allocate an array full of zeros
of the right type.

Also use a saner way to compute the output dimensions.

All the checks will still be applied in the inner function at least once
on every input value. However, for subsequent calls of the outer
node on the same input values (for output memory checking), the inner
function call will be much faster.

That way, some instances of DebugMode can do the checks,
while others do not.