Add support for setting VirtualBox video ram in definition

Make use of VBoxManage modifyvm --vram command.
single ticks prevent modifyvm command from working at least in windows and consistent with other calls
Fix install order for guest additions. They can't be installed without development essentials
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
Tested reduction for memory footprint to 512MB. Updated for Fedora 18 Beta RC1.
Fix spelling error: "succesfully" --> "successfully".
fix openbsd50 architecture customizations
add openbsd 5.2
Merge pull request #438 from mpapis/master

OpenBSD fixes + new templates for 5.2
Synced templates into doc/template.md
Merge pull request #439 from winks/master

Synced templates/ dir with doc/templates.md
Update README.md

little typo in the filename "definition.rb"
Merge pull request #440 from mmaha/patch-1

Update README.md
respond with error if build can't find any definition
bumped version to include kvm improvements
allow definition name to contain plus
extract repeating code to one method
adding an option to skip iso transfer
Add a Puppet system user for Ubuntu Server 12.x
Fix GH-443 - make em-winrm optional and check gem for windows vms