make kibana friendlier to config mgt systems

this patch makes is easy to manage by setting application parameters
in a single init script by exporting them as environment variables,
sample/kibana.erb is an example of such a script

KibanaConfig and kibana-daemon in turn read in those environment
variables

kibana-daemon.rb has been updated so it can read in env vars for
handling logging and location of the pidfile
Merge pull request #286 from bryanwb/cm_friendly_init

make kibana friendlier to config mgt systems