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
Tested reduction for memory footprint to 512MB. Updated for Fedora 18 Beta RC1.
Fix spelling error: "succesfully" --> "successfully".
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
Add a Puppet system user for Ubuntu Server 12.x
Fix GH-443 - make em-winrm optional and check gem for windows vms
released new version because of major bug
Merge pull request #447 from bkg/puppetuser-ubuntu12.x

Puppet requires a user/group for Ubuntu Server 12.04
FIX GH-445 - Return non zero exitcode when template is missing
Merge branch 'master' of github.com:jedi4ever/veewee
make use of Regexp.escape instead of manually escaping with gsub
new release
Merge pull request #441 from mpapis/bugfix/fix_plus_in_definition_name

allow definition name to contain plus