Begin ModuleSet specs.
Move all Launcher dependency injection to config DSL.

The Launcher no longer accepts an options hash.
Remove dead code in Launcher.
[breaking change] Move module DSLs into ModuleSets.

This will break your config.rb files, as this:

```ruby
driver :foo, Bar do
  # ...
end

server :baz, Shpee do
  # ...
end

enable_driver :foo
enable_server :baz
```

is now this:

```ruby
drivers do
  configure :foo, Bar do
    # ...
  end
  enable :foo
end

servers do
  configure :baz, Shpee do
    # ...
  end
  enable :baz
end
```