Tweak kitchen.yml & service restart

Hi,
* Tweaked service restart as suggested by @webframp
* Had to explicitly add apache2 to the runlist again, otherwise its attributes are not available to carbon.conf template (which is created before the web.rb recipe includes the apache2 cookbook).
* Re-added yum::epel to centos, as mod_python package is from EPEL.
* Centos 5.8 doesn't have the python-twisted package in its default repos, so I disabled it for now till we figure out where to take it from (maybe use a different package name?)


Note that the timing in which parts of dependent cookbooks are loaded differs by chef version...