Revert "force pybuild to use setuptools"

This reverts commit 1c444ad8f5ff31b288a12dce7db11dc16103f620.
Revert "update debian package to use pybuild"

This reverts commit 2ab2369dd74ef5622b719c35a5beec6e683ebe34.
Merge pull request #578 from nikicat/master

added memory_docker collector
Fix diskspace collector's formatted disk names.
Merge pull request #579 from chrisbolt/master

Fix diskspace collector's formatted disk names.
memory_cgroup: added memory limit metric
memory_docker: fixed tests