Fixed getUnix() utility in CudaPath so that it finds the cuda installation.
Added architecture parameter. This allows you to specify to rootbeer if you want 32bit only, 64bit only or both (by either omitting the parameters or putting both of them). This also fixes/sidesteps the issue we have with the CUDA 5.5 installation and 32bit headers not being found on 64bit ubuntu 13.04 since we can tell it to only generate 64bit binaries.
fixup last commit. now user can choose nvidia 32/64 bit arch. see below.

Reported and fixed by Gabriel Rossetti.
On some 64bit machines, compiling the 32bit version results in an
error from nvcc saying "cuda_runtime.h" not found. Originally
rootbeer compiles both for 32bit and 64bit. Now you can choose with
the following options.
  $ java -jar Rootbeer.jar -runtest SimpleTest -32bit (32bit only)
  $ java -jar Rootbeer.jar -runtest SimpleTest -64bit (64bit only)
  $ java -jar Rootbeer.jar -runtest SimpleTest        (32/64 bit)

This option is related to compiling the code. If you want your
compiled jar to run on both 32 and 64 bit systesm, you must
use the (32/64 bit) option. The 32bit compilation option will
only run on 32bit systems and the 64 bit option will only
run on 64bit systems.