User should have more than one try to fill username and password

[optak]

If I use registration plugin without saved ceredentials (in Vagrantfile), I have just one try to fill username and password correctly and if I make error, I have to do "vagrant halt && vagrant up".
It would be nice if this plugin support one of this options:

1. allow for example 3 attempts to fill credentials
2. give a hint how to do it manually after "vagrant ssh"

[strzibny]

I think it would complicate the current codebase for something that is not used so often, but perhaps we should offer vagrant (un)register commands that can be ran anytime user wants. Running them could be then a 'hint' you are talking about.

[hferentschik]

Can we add the label focus:devex to this one?