metatags 7.x-1.0-alpha1

Changes since 7.x-1.0-unstable3:

• Lighten up grey for details section.
• Stop table from messing up on collapse/expand.
• Adding missing arrow images.
• Show messages on enable/disable. Cleanup row handling.
• Display text if config has no overridden values.
• Added coloring for disabled rows.
• Massive improvements to the administration UI.
• Fixed invalid meta tag og:picture should have been og:image.
• Renamed hook_metatag_context_info() to hook_metatag_config_instance_info(), added helper functions to get parents and label of a config instance, unified config messages and titles.
• #1278082: Added descriptions for meta tags.
• Added link to Metatags configuration in admin/modules.
• Remove default config for 'node:article' as we don't know if the site will have an Article node type, and it also encourages usage of the keywords metatag.
• #1277532: Increase default textfield limit to 255 characters.
• #1277838: Added support for the global and frontpage metatag context output.
• #1281104: Added support for the Robots meta tag.
• #1278794: Prevent the metatags fieldset from showing up twice in vertical tabs if field_collection is enabled.
• Added metatag_metatags_values() and allowed metatag_filter_values_from_defaults() to use information in hidden default fields.
• Simplify the vertical tabs text.
• Allow a no-value option for the Open Graph type meta tag.