metatag 7.x-1.0-beta4

This is a high-priority update for any sites running beta3 - it fixes problems in the update scripts that adds the new language field, and hides unnecessary errors until the database updates are ran. This release also adds several new features & important bug fixes since beta2, so all sites should upgrade.

Most notable improvements since beta2:

• Support for Entity Translation.
• Twitter Cards meta tags have been added.
• A bug in the Features integration has been fixed.
• Support for CTools-driven (Panels, Panelizer, etc) page displays for entity pages.

Full changelog since 7.x-1.0-beta3:

• #1842764 by DamienMcKenna: Work around problems in metatag_entity_load() stemming from an outdated database schema, leave a message suggesting the site admin run the database updates.
• #1842868 by DamienMcKenna: Changed metatag_update_7003 to automatically assign the correct language per entity, added update_7004 to fix records updated in beta3, fixed the language selection for loading meta tags so sites without translation functionality continue to work correctly.
• #1842868 by DamienMcKenna: Changed update 7003 again so it *only* adds the new field, changed update 7004 so it will update all records using Batch API.
• #1843676 by DamienMcKenna: Changed the hook_requirements message to an INFO message if Page_Title is also installed, will freak people out less.

This also includes all changes from beta3:

• #1688286 by colan, DamienMcKenna: Support for Entity Translation.
• #1835030 by DamienMcKenna: Documentation and hook_requirements note re Drupal core v7.17.
• #1840402 by DamienMcKenna, paperdhc: Corrected use of array_pop().
• #1841404 by mh86: Don't attempt to load meta tags for unsupported entities, and don't support configuration-only entities.
• #1841564 by peximo: Correctly identify the content language being used on the homepage.
• #1841774 by DamienMcKenna: Provide a warning via hook_requirements if the Page Title module is also enabled, due to the possibilities of complications and unexpected results.
• #1363476 by DamienMcKenna: Workaround to trigger metatag_entity_view() if the current CTools (Panels, Panelizer, etc) page is an entity display page.
• #1842052 by DamienMcKenna: Don't process unsupported entities being displayed via Views.
• #1664322 by nico059, kerasai, miechiel, idflood, DamienMcKenna, alexweber: Twitter Cards meta tags.
• #1842198 by DamienMcKenna: Move the 'advanced' fieldset under the others.
• #1840236 by weri, Marty2081: Only revert the requested feature, not all features.