Changed UKhadron import routine to import complex part.
Added example for computing eigenvalues of Dirac operator.
Removed pointless modulo operator in linear operator utils
Added cuda kernels and linear operators.

The added files contain code that resembles that src/linear_operators.
Linear operators are based on the cusp::linear_operator type. I've
created a LinearOperator base class, just like in src/linear_operators,
which transfers the links to the GPU. Everything is based of this class.

The CUDA kernels are in kernels.h and kernels.tcu, and some utilities
are in utils.h and utils.tcu. There's a generalised hopping kernel,
along with a diagonal kernel.

Since utils and kernels use templates (in the hope of optimizing the
calculation), the implementation for these is in tcu files, which are
included at the end of the header files.
Added 3d hopping kernel to cuda kernels.
Rename VectorType and added VectorTypeHost as we'll need both.
Added propagator types to utils.h
Added file with interface functions to handle cuda inversions.
Added code to cuda LinearOperator to access L, T and links_
Fixed bug in computation of dimBlock and dimGrid
Added code to dimBlock and dimGrid calculation to check max available threads
Added scalar value assignment kernel to cuda utils.
Added cusp blas file to cuda utils.h as the fill function will be useful.
Added cusp copy header to cuda utils - this will be needed later.
Added make source function to cuda interface.
Swapped to using cusp::blas::fill for filling out vector with zeros

This is in invertDiracOperator in cuda interface.
Implemented generic propagator generation routine in cuda interface
Added deletion of smearing operators in Propagator generation cuda code
Remove const from definition of psi in cuda invertDiracOperator.
Added Wilson Dirac operator inversion cuda interface.