(RE-1535) Restore previous template behavior

Previously, debian templates would be automatically evaluated and
included in tarballs. This functionality was lost at some point. This
commit works around the issue by sourcing the template from the root if
it doesn't exist in the workdir. If it is not available in either
location it exits with a helpful message.
(maint) Add http:// to the link given to users to make it clickable
Merge pull request #286 from haus/maint/master/add_http_to_link

(maint) Add http:// to the link given to users to make it clickable
Merge pull request #285 from haus/ticket/master/re_1535

(RE-1535) Restore previous template behavior
Deprecate mkdir_pr, replace uses with FileUtils.mkdir_p

mkdir_pr is equivalent to a FileUtils.mkdir_p invoked with an array of
directories to create. This commit deprecates the mkdir_pr utility
method, and replaces all current invocations to use the FileUtils method
instead. The method itself is updated to pass its args directly to
mkdir_p instead of looping over them, as mkdir_p can handle a list of
directories.
Deprecate ln, update calls to use FileUtils.ln

The utility ln method provided by packaging does very little to augment
the FileUtils version. Our utility reverses the arguments and passes
some options. This commit updates any current calls to ln to use
FileUtils.ln and pass in the force and verbose flags, as is already
done. In tests, it looks as though the utility method is never invoked,
probably because of how rake requires and includes FileUtils. It also
deprecates the utility method, for future removal.
Deprecate ln_sfT

No tasks or methods currently use the ln_sfT method, so this commit adds
a deprecation for it, paving the way for a future removal of the method.
Merge pull request #287 from haus/maint/master/deprecate_some_utilities

Deprecate some of these utilities that are bad
Add cow_list method to Pkg::Config

Currently our debian changelogs are littered with inaccurate lists of
debian platforms. Updating all of those lists independently of the
build_defaults file seems like a duplication of work. This commit
addresses that by making available a simple method to get a space
separated list of debian platforms for a project.
(maint) Correct cow_list comments to say return instead of print