Puppet/apache: Exec 'iptables-allow-http' only for RedHat, CentOS and Fedora

Debian and Ubuntu do not deny incoming HTTP connections by default.
Vagrant: Rename icinga-web to icinga-web-mysql
Puppet/nagios-plugins: Fix installed package name and source repo
Puppet/icinga-mysql: (Re)start service icinga after ido2db has been installed
Puppet/php::extension: Fix useless extending of require
Puppet/xdebug: Move xdebug code from php module to the new xdebug module