pkg: move debian to new deb folder.

Initial effort to support several deb distributions.

(cherry picked from commit c27850a2a258a723cd807a8431719607f49f0dcf)
pkg/debian: add 1.5.1~dev version to changelog
pkg/deb/debian: Upgrade debian packaging.

(cherry picked from commit 7f301def7fccf4c91733ec105286c37989b03647)

Conflicts:
	pkg/deb/debian/compat
	pkg/deb/debian/control
	pkg/deb/debian/rules
	pkg/deb/debian/sems.default
	pkg/deb/debian/sems.init
pkg/deb: add jessie, wheezy and precise distributions