Update interface of test-cases generator.
Reduce number of generated test cases.

Cancel changes into dnn_fwd.c
Heavy simplification of check_dnn.
Make check_dnn runnable as a python script.

- add sub-module check_dnn_doc.py to help check if tests
  fail as expected from cuDNN documentation.
- re-organize whole code into `check_dnn.py`.
- add a test case generator.
- add classes to help choose algos at runtime without actually
  computing convolution.
- Separate exhaustive tests and tests for choosing algos at runtime.

with list of deterministic algorithms
and other utility definitions.

that take algo, alpha and beta as parameters.

Rewrite tests to handle both 2D and 3D conv correctly.
Simplify gradinput and gradweight tests.

Synchronize configdefaults with #5964.

Disallow float16 precision for convolution gradients functions.

Use the right mask to check for alignement.

Make setup.py fallback when versioneer can't get the version.

ARange gradient (contd)

Upsamp2

correct gradient for ARange

Fixup by using the good num_step used and using DisconnectedType instead of zeros (This change what was requested), remove +1. Test another corner case.

Fix opt crash and crash/tests when SciPy is not there.

Try to fix test_mpi_roundtrip tests not finising. Use Popen.communicate as it can prevent OS deadlock from Python doc.

Generalised AllocDiag for more than 2D input

buildbot release test without scipy