Inject plugin_info object into plugin implementations as well

docs/plugins/concepts.rst

@@ -299,6 +299,8 @@ An overview of these properties follows.
   The plugin's name, as taken from either the ``__plugin_name__`` control property or the package info.
 ``self._plugin_version``
   The plugin's version, as taken from either the ``__plugin_version__`` control property or the package info.
+``self._plugin_info``
+  The :class:`octoprint.plugin.core.PluginInfo` object associated with the plugin.
 ``self._basefolder``
   The plugin's base folder where it's installed. Can be used to refer to files relative to the plugin's installation
   location, e.g. included scripts, templates or assets.

src/octoprint/plugin/core.py

@@ -902,6 +902,7 @@ class PluginManager(object):
 				identifier=name,
 				plugin_name=plugin.name,
 				plugin_version=plugin.version,
+				plugin_info=plugin,
 				basefolder=os.path.realpath(plugin.location),
 				logger=logging.getLogger(self.logging_prefix + name),
 				))