caffe conv kernel for theano. tests work, but needs integration and some...

- changed conv to corr as suggested by Fred

Only create the handle if we specify a device to gpu_init().

[CRASH,DOC,ENH] Mixed

mostly useless.

Including support for 'full' convolutions. It uses the existing pad functionality of the c/cuda code. If mode == valid, I make pad = filter_size -1. This is passed to the C code, and everything else gets taken care of automatically.

The theano-nose for test_full does not pass, however, the test function test_gemm()  passes. @nouiz: do you know why?

Fix compile on cuda < 5.0.

[CRASH] Be more resistent to NumPy bad strides for shapes of 1.

[TEST fix] Fix debugmode checking in python3

Merge commit 'refs/pullreqs/origin/pr/2' into conv_gemm after Fred's commit which said valid finally works.

- added a test that does a check on variety of shapes and sizes of image and kernel
- removed flip form local_conv_gemm in cuda/opt.py is the code never reached there for me
- added flip in the kernel in the test code itself

[CRASH] Conv2d none