Updated puppet-rvm to latest version.

The one being used before was at least 7 months old and had considerable differences from the latest.
Allowed rvm to install the latest version of ruby-1.9.3 while avoiding problems for using "rvm use" later on. The "-p0" at the end was causing the problem.
Also, included ruby-2.0.0 latest.
A default_use flag is present now, just so it is easier to overwrite in case one needs to.
Fixed problem where environment would not be provisioned on first run.

According to https://github.com/mitchellh/vagrant/issues/2421, the default behavior was changed since Vagrant 1.3.0 on is to not provision new boxes after the first run unless you specify either "vagrant up --provision" (to bring it up after a "vagrant destroy") or "vagrant reload --provision" or "vagrant provision" for a running instance.

In order to fix it, I removed the 'if $rvm_installed == "true"' condition. The purpose of that condition to begin with, is to avoid an error that comes up when running puppet with --noop (as specified at https://github.com/blt04/puppet-rvm/tree/master under the Troubleshooting / FAQ section). Since $rvm_installed is evaluated at the beginning of each puppet run, that fix however has the side effect that if you use this in your manifest, you will need to run puppet twice to fully configure RVM.
Updated readme file.

It dispenses of the "vagrant reload" instruction since it is not needed now.

It adds a remark about using "vagrant ssh" on windows.

It adds a note about getting ssh information.

The latter two pieces of info were retrieved from http://docs.docker.io/en/latest/installation/windows/