Add '--scripts' parameter to set the path to custom preinstall and postinstall scripts
Add 'scripts' option in README
Check for presence and set permissions for pre and post install scripts
Clarify the use of the --scripts option
Preserve ownership of files (and prevent the default root-owned files)
Customize ownership as an option passed through to pkgbuild

Reverts back to the previous default behavior and add custom ownership
as an option