Change the run-time behavior of the automatic assignment of JCCL_BASE_DIR back to the way it worked prior to r20760. Namely, the work to set JCCL_BASE_DIR automatically is only performed if the environment variable is not already set. Further, JCCL_DATA_DIR is now set relative to JCCL_BASE_DIR whether it was assigned automatically by this code or manually by the user.
Change the run-time behavior of the automatic assignment of JCCL_BASE_DIR
back to the way it worked prior to r20760. Namely, the work to set
JCCL_BASE_DIR automatically is only performed if the environment variable is
not already set. Further, JCCL_DATA_DIR is now set relative to JCCL_BASE_DIR
whether it was assigned automatically by this code or manually by the user.


git-svn-id: a341ccba1312b2efdbe34f40faf90581f48aa49f@20767 08b38cba-cd3b-11de-854e-f91c5b6e4272

LiuKeHua/vrjuggler,vancegroup-mirrors/vrjuggler,LiuKeHua/vrjuggler,MichaelMcDonnell/vrjuggler,vrjuggler/vrjuggler,vrjuggler/vrjuggler,vrjuggler/vrjuggler,LiuKeHua/vrjuggler,LiuKeHua/vrjuggler,MichaelMcDonnell/vrjuggler,MichaelMcDonnell/vrjuggler,godbyk/vrjuggler-upstream-old,vrjuggler/vrjuggler,vrjuggler/vrjuggler,LiuKeHua/vrjuggler,godbyk/vrjuggler-upstream-old,vrjuggler/vrjuggler,MichaelMcDonnell/vrjuggler,vrjuggler/vrjuggler,godbyk/vrjuggler-upstream-old,MichaelMcDonnell/vrjuggler,MichaelMcDonnell/vrjuggler,godbyk/vrjuggler-upstream-old,vancegroup-mirrors/vrjuggler,vancegroup-mirrors/vrjuggler,vancegroup-mirrors/vrjuggler,LiuKeHua/vrjuggler,MichaelMcDonnell/vrjuggler,vrjuggler/vrjuggler,vancegroup-mirrors/vrjuggler,LiuKeHua/vrjuggler,LiuKeHua/vrjuggler,MichaelMcDonnell/vrjuggler,godbyk/vrjuggler-upstream-old,godbyk/vrjuggler-upstream-old,vancegroup-mirrors/vrjuggler