remove hhvm restart from nginx api recipe
use attributes for config file paths

+ reverse order in init.d script:
(the SYSTEM_CONFIG_FILE seem to overwrite the settings
in the other one)
added config.hbf hhvm config

"documentation" at https://github.com/facebook/hhvm/wiki/runtime-options
fix CI errors

+ first try of a chefspec test for hhvm-fcgi