(maint) Remove stale files from ext/rack

The ext/rack directory had an outdated README file and an ancient manifest.pp
file, and the useful files (config.ru and the example vhost) were buried in a
subdirectory.

This commit removes the old files, moves the good files up a level, and adds a
comment to the vhost pointing to the maintained passenger documentation.
(maint) Update debian packaging to reference new rack support location

As updated in commit 4c9b63f, the sample files for rack passenger deployment
have been moved up a directory. The puppetmaster-passenger package for debian
uses those files, so this commit updates the debian/rules file with their new
location. It also updates the README_DEVELOPER.md, which references the same
files.
Merge pull request #1951 from nfagerlund/stale_rack_files

(maint) Remove stale files from ext/rack
(#23126) Allow facter and hiera gem locations to be SSH git URLs

Previously, git urls could only be specified as `git://`. This works
fine for pulling down the puppetlabs facter and hiera repos, but
doesn't allow private forks of those to be pulled down. This is
problematic because the Gemfile is used for setting up our test
environments and the PE versions of facter and hiera are accessed over
SSH.

This commit allows git@ urls in addition to the curreng git: urls.
Merge pull request #2054 from branan/ticket/23126/allow_ssh_git_gems

(#23126) Allow facter and hiera gem locations to be SSH git URLs
(maint) Remove ext/rack/README reference from debian/rules

In a previous commit, files in ext/rack/files were moved up a directory to
ext/rack and some unneeded files were removed. Among the removed files was
README, which was unfortunately still used in the debian/rules file as a
supplemental doc for the puppetmaster-passenger package. The lack of
ext/rack/README caused the rules evaluation to fail, which caused debian
packaging to fail. This commit addresses that by removing the README references
from the debian/rules file.
Merge pull request #2070 from haus/maint/stable/fix_rules_for_missing_readme

(maint) Remove ext/rack/README reference from debian/rules
(maint) Rename expected apache vhost in debian/rules

In a previous commit, files in ext/rack/files were moved up a directory to
ext/rack and some files were renamed. Among the renamed files was
apache2.conf, which was renamed to example-passenger-vhost.conf.  This caused
the rules evaluation to fail, which caused debian packaging to fail. This
commit addresses that by renaming the vhost references in the debian/rules
file.
Merge pull request #2071 from haus/maint/stable/fix_rules_for_renamed_vhost

(maint) Rename expected apache vhost in debian/rules
Merge branch 'stable'