Fix the dhcp clean up for Ubuntu 12.04 or newer's postinstall.sh

For more info, please see the Launchpad issue at https://bugs.launchpad.net/ubuntu/+source/isc-dhcp/+bug/910108
adding an option to skip iso transfer
DEBIAN 6.0.5: Change the mirror server to ftp.us.debian.org

This makes the "mirror does not support this release" error go away.
DEBIAN 6.0.6: Make the VM wor better on machines without VT extensions
add SLES-11-SP2-DVD-x86_64-GM template
added dkms to allow virtualbox dkms module to be created during virtualbox installation time
fix mixed options from symbols to strings for tests
KVM provider: Fixed undef method
KVM provider: Fixed Windows support

* fixed adding of floppy drive to KVM machines
* support for adding virtio drivers to KVM machines
Windows 8 templates

Added 32-bit and 64-bit templates for Windows 8. The ISO for the Windows 8 90 day evaluation will be used.
Merge pull request #466 from ffeldhaus/windows8-templates

Windows 8 templates
Add vagrant user to sudo group instead of admin.

The base distro has replaced the admin group with sudo in the standard
/etc/groups file.

The admin group need not be created if the vagrant user is added to
sudo group instead and /etc/sudoers is edited so that members of sudo
don't require a password.
Merge pull request #467 from lotia/ubuntu-12.04-admin-changes

Add vagrant user to sudo group instead of admin.
Fix typo
Merge pull request #471 from rubenv/patch-1

Fix typo
KVM Provider

- removed check for available gems. Requiring fog is sufficient to get meaningful error messages if either the fog or libvirt gems are not present
- set libvirt_uri and libvirt_ip_command parameters for the Fog libvirt provider if they are not already set in the fog config file
- use the fog libvirt provider instead of a libvirt directly to make use of the configuration settings in .fog
- the availability of at least one storage pool and network is now checked through fog methods
- the libvirt version is now checked through the fog method
- the connection to libvirt is not closed as it gets automatically closed when the garbage collector deletes the variable
KVM Box

- removed requiring of libvirt and fog gems as this is now handled in the KVM provider class
- removed the options for creating the libvirt connection as these are now handled in the KVM provider class
KVM validate

- removed vbox tag and added kvm tag
KVM documentation

- extended the documentation with more details on prerequisites and usage of the kvm provider
Merge pull request #472 from ffeldhaus/kvm-provider

KVM provider: restructured to always use Fog.io to connect to libvirt