environment variables.

* The $NPTOOL env. variable is now the only one to be defined for
  running the project.

* Add comments in the $NPTOOL/NPLib/liblist file to specify that
  this file is created automatically.

   + scripts are used to move header files, libraries to the include and
     lib directories
   + scripts are located in NPLib/scripts
   + liblist is know created on the fly and is removed from the NPTool 
     package

* Update NPL Makefile to include Paris and Shield detectors