Bug Fixes, initial Distributed support

A bugfix release with some small features:

New Features

• THPP now has CUDA Tensors
• autograd functions: repeat, var, std, renorm, comparison ops added.
• Merged an initial version of THD (distributed pytorch)
• Indexing support with LongTensor indices
• Add torch.unbind
• Add ModuleList and ParameterList to store lists of modules / params in an nn.Module

Bug and usability fixes

• Fix a bug in FFI utils
• Fix lua-reader for SpatialConvolution
• Fix backward contiguous check in BatchNorm
• Fix travis builds
• Pep8 enforced for the entire codebase
• CuDNN RNN non-contiguous fixes
• Remove circular references in some Autograd functions
• Add CUDA asserts to various kernels for out-of-bounds checks
• Fix non-contiguous bug in torch.cat
• Fix memory leak in Unpooling

API Changes

• nn.Billinear* -> nn.Bilinear*
• Return indices as well in autograd for torch.sort and torch.topk
• .set_index -> ._set_index (made private)
• normal and log_normal kwarg changed from var to std
• Optimizer.state_dict now has semantics matching Module state_dict