Various fixes for debian/ubuntu packaging

- update created set of dirs
- make /var/log/losgtash owned by logstash
  (this patch might need root priviliges)
- remove redundant set of ubuntu/ files which
  are not different to debian/ set of files
- create /etc/logstash for ubuntu and debian also
- merge logstash user and group creation in
  one command
- uniformly make /opt/logstash $HOME for
  logstash user
- let userdel remove $HOME
- confdir = /etc/logstash
- use full path to jar file in upstart script
- add some extra options to fpm that were
  undefined but desirable

This patch was intended to update debian/ubuntu
specifics. Some minor trivial things were
consequently updated to redhat, but those could
not be tested.