debian: Remove unused dh_make templates
debian: Add debian/source/format
debian: Update debian/copyright

Make the contents match reality, and use new Debian machine-readable
format for debian/copyright.
debian: Update Java dependencies to current policy
debian: Reimplement rules using dh

This greatly simplifies things, and also fixes a number of latent bugs,
especially confusion about architecture-dependent and -independent
packages.

Also update debhelper compat level and standards version.
debian: Remove /var/run/jenkins from package

Putting this directory into the package is an error because /var/run can
be on a temporary file system.  The init script already takes care of
creating this directory, so this wasn't necessary anyway.
debian: Move dirs to jenkins.dirs for consistency
debian: Update package description style
Merge pull request #956 from petere/debian-cleanup

Debian cleanup