Added a function to look through the system path for an executable.
Added a function to look through the system path for an executable.

brunyuriy/crystalvc,KaranDagar/crystalvc,SoftwareEngineeringToolDemos/FSE-2011-Crystal,brunyuriy/crystalvc,SoftwareEngineeringToolDemos/FSE-2011-Crystal,KaranDagar/FSE-2011-Crystal---old,KaranDagar/FSE-2011-Crystal---old,KaranDagar/crystalvc,SoftwareEngineeringToolDemos/FSE-2011-Crystal