most of this deletes useless old code.

the change to lookup_provider_constant changes to more strictly
stop using class name based lookups and to go through the resource
resolver and provider resolver.

as a result in order to find the provider class for a given dsl name
you have to go through the resource resolver to find the resource in
order to be able to pass a resource instance through the provider
resolver.  since the provider resolver api passes resources into blocks
passed into provides api you must construct a resource instance.

that means that providers need to be associated with resources in order
to be looked up (which makes sense in Real Life(tm) use of Chef, but
breaks quite a few lazy tests we had where we constructed providers
without doing the work of wrapping them in a resource.

note that as the deploy resource shows this filters into a changed
behavior of the `provider` syntax where before `provider :revision`
would look up Chef::Provider::Deploy::Revision via class-name based
magic.  this breaks that API so that `provider :deploy_revision` is
used instead -- the symbol (or string) there is turned into a resource
first via the Chef::ResourceResolver and then looked up via the
Chef::ProviderResolver into Chef::Provider::Deploy::Revision.  this
is a breaking change but is also a bug fix so that the symbol here
goes through the same lookup that you get when you type it in the DSL.

i had considered implementing a lookup from a resource_name symbol to
a provider, but in looking at how to implement that in the
ProviderResolver the issue is that we really need to have a resource
instance order to pass to the ProviderResolver.

Signed-off-by: Lamont Granquist <lamont@scriptkiddie.org>