…_data block of Kernel plugin
if chef version is 11.8.2 and it pins ohai to <~ 6.0, then if we install ohai 7, the chef plugin will attempt to load chef up and then will puke hard since ohai 7 is already loaded. this just skips chef version detection if that dependency resolution problem occurs.
The previous logic instantiated plugins as the files were read. This caused multiple instances of plugins to be created when a plugin is "reopened" in another file. Additionally, loading-specific logic is moved from System to Loader.
This greatly speeds up running ohai from the command line when given a set of attributes to display (like `ohai ec2`). Prior to this patch, ohai would run all plugins and then filter out the data. With this patch, ohai only runs relevant plugins. As an unscientific test `bin/ohai network` on my laptop takes ~4s without this patch compared to ~1.1s with the patch.
…en't syntax errors