Changes to allow for smoother setup with system Boost and using the CUDA Runtime library.

Having the default value for USE_SHIPPED_BOOST puts users who wish to use their system
boost in a bad situation, since if they include --use-shipped-boost as an argument to
configure.py, they have to use PyCUDA's Boost, and if they don't, they still have to
use PyCUDA's Boost.  I've changed it to false here.

Adding information about CUDART and friends helps with compiling the CURAND module,
as well as with other projects that interoperate with CUDA Runtime model code.