Although there aren't any Jenkins packages deployed that use a launch daemon, soon there will be.
Let's make the preinstall capable of handling that already now.

Files under /Applications are usually owned by root and wheel, unless admin user has dragged it there. Jenkins is not an install-by-dragging kind of app.

The Jenkins launch daemon is configured "RunAtLoad", i.e. it runs immediately. No need to start it.

- make the file name match the existing scheme.

Open the configuration directory, not the Jenkins
folder in general

Before, the image was fairly bright, and
overwhelmed  other elements in the installer
window

THe installer will say everything is invalid

It follows an identical calling syntax to the
build scripts used by the Debian, OpenSUSE, RPM
and MSI build processes.

Forgot that this was textile and not Markdown, so
line breaks matter.

Reference:
http://developer.apple.com/library/mac/#documentation/DeveloperTools/Conceptual/PackageMakerUserGuide/Workflow/Workflow.html#//apple_ref/doc/uid/TP40005371-CH1000-SW26