Improvement. Only set the install prefix if the enviroment variable is not set.
Improvement. Only set the install prefix if the enviroment variable is not set.


git-svn-id: 5069ba8be4c997ee907bf46f8ec9a2bbfb655637@1384 e59a4935-1847-0410-ae03-e826735625c1

linpc/STP,linpc/STP,linpc/STP,linpc/STP,linpc/STP