Safer bin/jenkins.sh

If someone runs bin/jenkins.sh without first setting $WORKSPACE,
don't cd to their home directory and start rampaging around.
Just use the current directory.
Merge pull request #918 from dpoirier/safer-jenkins.sh
Bug 730627 Fix donottrack.us link text
Merge pull request #921 from retornam/bug-730627-donottrack

Bug 730627 Fix donottrack.us link text