Adding multi-file scp
only works with Ruby 1.9+
SSH returns 255 for connection refused errors.

So limiting the range down a bit.
Making it work again with fog 1.10

in 1.9, the original code was sufficient, but 1.10 has a massive
refactoring in the way of registering providers. Unless at least one
provider is registered, the providers hash is empty, and it causes
an exception like the following:

/var/lib/gems/1.8/gems/fog-1.10.0/lib/fog/compute.rb:39:in `new': undefined method `include?' for nil:NilClass (NoMethodError)
    from /home/kohsuke/ws/cloudbees/blimpy/lib/blimpy/boxes/aws.rb:39:in `fog'
    from /home/kohsuke/ws/cloudbees/blimpy/lib/blimpy/boxes/aws.rb:32:in `validate!'
    from /home/kohsuke/ws/cloudbees/blimpy/lib/blimpy/fleet.rb:110:in `start'
    from /home/kohsuke/ws/cloudbees/blimpy/lib/blimpy/fleet.rb:109:in `each'
    from /home/kohsuke/ws/cloudbees/blimpy/lib/blimpy/fleet.rb:109:in `start'
    from /home/kohsuke/ws/cloudbees/blimpy/lib/blimpy/cli.rb:73:in `start'
    from /var/lib/gems/1.8/gems/thor-0.18.0/lib/thor/command.rb:27:in `__send__'
    from /var/lib/gems/1.8/gems/thor-0.18.0/lib/thor/command.rb:27:in `run'
    from /var/lib/gems/1.8/gems/thor-0.18.0/lib/thor/invocation.rb:120:in `invoke_command'
    from /var/lib/gems/1.8/gems/thor-0.18.0/lib/thor.rb:363:in `dispatch'
    from /var/lib/gems/1.8/gems/thor-0.18.0/lib/thor/base.rb:427:in `start'
    from /home/kohsuke/ws/cloudbees/blimpy/bin/blimpy:24

By forcing the registration of a provider, it works against with fog
1.10. Looking at the source tree, this change should also work with fog
1.9.
Fixed a system/local conflict problem

If blimpy gem is already installed, this ends up picking blimpy from the installed gem, as opposed to the local workspace.
Fixing the unit test failure

Since these tests do not use any livery, explicit wait_for_ssh command
is required
If Blimpfile is invalid, report why