Revert 2 commits.

Revert "implement preexec_fn for environments"
This reverts commit 3fc5d8e43301f26aae8b0a18d554c81009b99a64.

Revert "Allow /usr/local to access"
This reverts commit d232cea63b1d2fd5beabd992e0dfbecd7d412e23.
Add rpath option