Fix enable/disable services notation

* The enable/disable_service functions want a space separated
  list of services name
* The disable_service function only disable services that are
  enabled by default in the ENABLED_SERVICES list. Since q-meta,
  q-dhcp and q-l3 are not enabled by default, we don't need to
  disable them.

Change-Id: Ib3d8be001063d09e0bb13aeb2fe7e6aaea6bc640
Signed-off-by: Rosario Di Somma <rosario.disomma@dreamhost.com>
Remove old comments

Change-Id: I483f90961b25fd6b36bb08056b0c221ab4bf5c78
Signed-off-by: Rosario Di Somma <rosario.disomma@dreamhost.com>
Merge pull request #16 from rodis/feature/fix-enabled-service-notation

Feature/fix enabled service notation