Flatten C code

[BUG] pool with padding

do not try cudnn opt when it isn't available

Set borrow=False for scan inner inputs

Add missing `host_from_gpu` import to `cuda.opt_util`

[WIP] Mechanism for running a test multiple times with different random seeds

Allow dnn convolution to work inplace

Update aa.py, theano.sandbox.wraplinker seems not exist.

Fix few tests for the nightly buildbot

Dnn pool support of pad

adding documentation to  addbroadcast() unbroadcast() and patternbroadca...