Need an extra package if we're using debian for rabbit clustering.
Merge pull request #147 from edx/jarv/single-instance-fixes

Jarv/single instance fixes
Externalize the debian packages.
Merge pull request #149 from edx/feanil/rabbit_debian_support

Need an extra package if we're using debian for rabbit clustering.
creating common var file for common pkgs
default edx_sandbox config does not launch instance