Update dependencies

Bump Omnibus to 2.0.0rc1.  Also, Opscode recently merged my OpenSSL
pull request and everything builds cleanly on Arch out of the box,
so revert back to using the master branch of the official
omnibus-software repository.
Fix vagrant-wrapper after Hashicorp changes

Hashicorp recently deleted their puppet-modules repository which
we were dependent on for the vagrant bin script that correctly
sets up the necessary environment variables for Vagrant and executes
the executable from the gem.  As a quick work-around simply pull a
recent copy of that script, make it available in a new repository
(also called vagrant-wrapper) and switch to using that.

I compared the wrapper script with the current official way of
packaging Vagrant to ensure the script will continue to work with
newer releases.  Whenever the Vagrant team settles on a final
packaging system we can consider replacing this wrapper script
with something based on upstream's work, but in the meantime I
don't anticipate any major difficulties keeping this approach
working.
Update to Vagrant v1.4.3

Upgrade to Vagrant v1.4.3 and add a patch to drop the dependency on
vagrant-spec.  I think vagrant-spec is a good idea and I commend the
Vagrant developers for their efforts on it.  Unfortunately, vagrant-spec
release don't appear to be in sync with vagrant releases; in fact,
vagrant-spec has no releases at all.  Unfortunately, this means that
unless you build your Vagrant packages at the time of the official
release there is no guarantee that the latest changes in vagrant-spec
as of the time you build Vagrant packages will still be compatible
with the Vagrant release you are trying to build.  *sigh*

Just drop the dependency and hope Mitchell, et al get their act
together in the future.