metatag 8.x-1.0-beta12

This release fixes a problem when using custom entities and Drupal Console, adds all of the mobile meta tags from the D7 release, adds Google CSE meta tags, adds the hreflang=x-default meta tag, and adds placeholders for all of the additional meta tags that will be added in future beta releases.

Full changelog since 8.x-1.0-beta11:

• #2823811 by Michelle: metatag_open_graph_preprocess_html() was misspelled.
• #2654148 by penyaskito, DamienMcKenna: Not all entity.*.add paths are tied to a specific entity form, so don't assume they are; this fixes compatibility with the Lingotek module, possibly others.
• By DamienMcKenna: Fixed a typo in README.txt.
• #2824442 by jiff: image_src should be a 'link' tag.
• #2821476 by DamienMcKenna, Daniel_Rose: Added tests to confirm entity defaults inherit properly.
• #2836124 by DamienMcKenna: Fixed tests for the Dublin Core meta tags.
• #2786625 by DamienMcKenna: Added the hreflang=x-default meta tag.
• #2532588 by DamienMcKenna, renatog, cebasqueira: Added the Google CSE meta tags.
• #2563631 by DamienMcKenna: Added a placeholder to store the AppLinks meta tags.
• #2809351 by DamienMcKenna: Added a placeholder to store the DC Advanced meta tags.
• #2835925 by DamienMcKenna: Added a placeholder to store the OG Products meta tags.
• #2563633 by DamienMcKenna: Added a placeholder to store the favicon meta tags.
• #2532588 by DamienMcKenna: Follow-up to fix the group assignment of the Google CSE meta tags.
• #2786625 by DamienMcKenna: Follow-up to fix the group assignment of the hreflang x-default meta tag.
• #2563635 by jlbellido, DamienMcKenna: Ported all of the mobile meta tags to the new Metatag Mobile submodule.
• #2840222 by jmolivas: Update for Drupal Console rc13 namespace changes.