Ability to define configuration classes on plugins
V1 config loading using plugins as a source for config keys
Config merging
Move core config into a plugin
Loader uses the new configuration classes
Get rid of the UNSET_VALUE stuff, save it for v2
Remove old configuration classes
Start moving guest configuration out into plugins
Add README to plugin directory
Major guests have been moved to plugins
Move all guests to plugins, even the distros
Add logging to v1 plugin registration
Move provisioners into plugins
Move hosts to a plugin system
Move commands into plugins
Fix some issues with commands not referencing proper classes
Get rid of provisioners directory
Remove hosts directory
Remove guest subdirectory
Remove old commands