add has_run? to plugin dsl, store plugin instance(s) with attributes
add license to loader_spec.rb
Ohai::Runner class for running plugins, add run_plugins to Ohai::System to run loaded plugins
add run_plugins specs to system_spec
fix cycle reporting
move version-specific dsl behavior to version class
switch from instance_eval to TOPLEVEL_BINDING eval in Ohai::Loader#load_plugin
Merge pull request #181 from opscode/OC-9012

Add dependency resolution to Ohai