Fix build on OS X 10.9 (Mavericks)

* version 0.5.1.0
* Make sure to #include stubs.h first everywhere
* CPP definitions to ensure that language-c can parse the Mavericks headers
* Properly link against the CUDA.framework on darwin
Fixed a library problem with CUDA 5.5. on OS X (Mavericks)
Put the CUDA library path into the package description

* This avoids the need to set [DY]LD_LIBRARY_PATH when loading the
package.
Improve the handling of CUDA.framework on OS X

* Set the framework field in the buildinfo file properly — allows us to
undo the fragile 72e2431c2c8d30cd0f8432efe22bac2b59da6dff
* Warn if we don't find nvcc
* Properly format help strings for compiler configure options
Merge pull request #4 from mchakravarty/mavericks

Fix build on OS X 10.9 (Mavericks)