Remove outdated macOS "Package Maker" configuration The tool is unavailable for many macOS versions and many years, so remove all related files.
PackageMaker: use relativ path names
Mac OS X: install on root volume only, and set correct permissions Update Mac OS X Installer.app description bundle, so that the ngIRCd package can only be installed on the root volume ("/"); and make sure that all installed files and directories have correct ownership and permissions.
Mac OS X: update installer texts and add logo.
New make target: "osxpkg" to create an Mac OS X installer package. This patch adds a new make target, "osxpkg", to the main Makefile which gereates a Apple Mac OS X installer package of ngIRCd. The packagemaker(1) project bundle is stored in contrib/MacOSX/ngIRCd.pmdoc.