Changed parent classes and added methods c_headers() and c_compiler() to ops GpuSoftmax and GpuSoftmaxWithBias.

Copy of tests test_softmax() and test_softmax_with_bias() from theano/sandbox/cuda/tests/test_nnet.py to theano/sandbox/gpuarray/tests/test_nnet.py

Copy of ops GpuSoftmax and GpuSoftmaxWithBias from theano/sandbox/cuda/nnet.py to theano/sandbox/gpuarray/nnet.py

Fix Gpu crash on windows

Fix crash during unpickling of Theano variable

Hide symbols in compiled modules

Minor fixes

Python3 compatibility in test program compilation

Similar fix to #1660.

Without this fix, a `'str' does not support the buffer interface` error is raised in Python 3.3 on Mac OSX 10.9. One place it occurs is during testing for the Mac OS sdot bug (line 73, blas_headers.py)

Faster opt

When an apply node execution raise an error, print the inputs values when they are scalars.

new Gpu reduce based on the version in Theano that is much faster.

Rename GpuCAReduce to GpuCAReduceCuda and reuse the name GpuCAReduce for GpuCAReduceCPY to allow reloading older pickled files.

Added the cumsum and cumprod functions similar to numpy's ones.