Merge lp://staging/~tribaal/landscape-client/make-package-building-dependencies into lp://staging/~landscape/landscape-client/trunk

(Almost a trivial)

This branch adds a makefile target to download and install required package building dependencies.
It allows to create (unsigned) packages super fast and conveniently with the following scenario:

sudo lxc-create -n saucy-base -t ubuntu -- --release saucy -b $(whoami)
(this takes a while the first time you install a new release, because it builds the base image locally. You need to run this command only once, ever.)

sudo lxc-start-ephemeral -o saucy-base
(login using your own user credentials)
sudo apt-get install make bzr
cd my-landscape-client-checkout
make package-deps && make pacakge
(play with your new package located in ../ . On shutdown this container is discarded)

Also, it is worth noting that the second time you run this the speed is amazing since the base image is built already, and your host machine will cache packages with apt-cacher-ng.