Updated setup.py to check for CSPICE library.
Updated setup.py to check for CSPICE library.

The setup.py now automatically calls the wrapper generator and can properly
name the cspice.a and csupport.a files when needed.  It needs to either have
the cspice directory in the project root or have the environment variable
CSPICE_SRC set.

rca/PySPICE,rca/PySPICE