added option to check strides of arrays returned by C functions. defaults to False because it is overly strict

a non-inplace DimShuffle of some view of underlying storage.  The bug would
result in the output strides being incorrect.  The bug is fixed by doing the
non-inplace copy part of the algorithm *before* calculating strides.

moved module documentation around, added tensor_wrapper so that constants in Modules turn into Constant Members

removed for easy_install).

Unittests should now call unittest_tools.verify_grad instead of
tensor.basic.verify_grad. The unittest version is simply a wrapper function
which takes care of first seeding the random number gen.

Updated the documentation accordingly