Vm allow gc of all intermediate results at the end of function call.

Only the lazy op cause intermediate result to don't be gc during compilation.

Small

The Updates object now check that the key are SharedVariable when we pass them in the __init__ function.

Add script to test PR.

those come from ipython that have the same license as Theano.

Doc

fix context problem with pycuda by checking it is imported before.

Opt

We already checked that the node is still in the env before we process it.

Also add the pycuda.init flag to force its import.

It is not needed to set it to True in the buildbot, as all test file
get imported before test start to run. So this init PyCUDA first if
the theano flag device and init_gpu_device are not used.

Bug reported by Nicolas regarding taps of scan sequences

ajout parametre keepdims

Small

Time opt

The bug was reported by Nicolas, and it happens when you have a single
tap for a sequence that is different from 0.