(PUP-2395) Update puppetmaster-passenger for httpd 2.4

In httpd 2.4 some of the conventions around a2ensite changed which broke
the postinst and postrm scripts. This commit brings in several changes from the
debian puppet packaging that have addressed this problem. An
apache2_puppetmaster_sitename function is used to determine the correct
sitename to use in sites-available. Thanks to Stig Sandbeck Mathisen for
the work in the debian puppet packaging.
(PUP-2395) Refactor puppetmaster-postinst sed calls

This commit brings over a change from the debian puppet packaging to
move all of the sed calls in to one sed invocation and to use a tempfile
instead of operating directly on the live apache vhost file.
(PUP-2395) Update puppetmaster-passenger postinst for passenger 4

Passenger 4 deprecated and removed several vhost directives, which would
break installations of the package on platforms with passenger 4. This
commit adds a condional sed call to delete those directives if the
passenger version is 4 or greater.