(PUP-2395) Fix puppetmaster-passenger for apache httpd 2.4

After Ubuntu 13.10 and in Debian Jessie, Apache httpd is at 2.4, which contains some breaking changes for the a2* utilities debian provides. Additionally, these platforms also move passenger to version 4, which has its own breaking changes. This PR updates the postinst and postrm for the passenger package to account for these changes, while maintaining compatibility with httpd 2.2 and passenger < 4.