iks: update and install iks configuration sample

+ update configuration sample with comments
+ install sample configuration to /opt/szarp/iks
+ default read config file at /opt/szarp/iks/iks-server.ini
iks: szarp-iks-server debian package

+ add szarp-iks-server package with binary and configuration file
+ add szarp-iks virtual package that pulls iks-server, apache and
  websocify
+ iks-server init script
+ dependencies in parstart init script
iks: creating pid file option

+ now there is an option to create pid file
+ pid file contains pid of server after daemonizing
+ in case of exception server returns error code
Restart iks-server with other szarp services

+ restart command of parstart init script restarts also iks-server
  server if installed. It doesn't start nor stop it.