Rename plugin to drupalentity
Rename command to editdrupalentity
Rename widget to drupalentity
Prefix config variables with DrupalEntity instead of EntityEmbed
Fix typo in docblock
Merge pull request #70 from cs-shadow/standardize-plugin-names

Standardize CKEditor plugin/widget/command names
Updated for https://www.drupal.org/node/1875996.
Fixed PHP notice if $form_state['values']['attributes']['data-entity-embed-display'] was not defined.
Fixed file field formatter description comes from config, not attributes.
Updated for https://www.drupal.org/node/2211227.