add definition for ubuntu 13.04 (server)
Update Debian 7.0 definitions from RC1 to release.

* Updated ISO URLs.
* Fixed failing virtualbox.sh on i386.
Merge pull request #679 from mickm/update_debian_wheezy

Update Debian 7.0 definitions from RC1 to release.
break up postinstall.sh
install libdbus and fix typos on VirtualBox Guest additions
remove existing VirtualBox guest additions before installing new version
remove ruby and rubygems source after installing them
add /opt/ruby/bin to the global path
Merge pull request #677 from ngpestelos/ubuntu-13-04

add definition for ubuntu 13.04 (server amd64)
Allow installation with obsolete gpg keys
Merge pull request #681 from rds13/master

Fix problem building VM for Debian 5.X from archive.debian.org
Merge remote-tracking branch 'upstream/master'

Conflicts:
	templates/ubuntu-13.04-server-amd64/definition.rb
	templates/ubuntu-13.04-server-amd64/preseed.cfg