metatag 7.x-1.9

This release fixes several bugs in the 7.x-1.8 release, particularly for translations and with the update scripts, and is a highly recommended update for all sites.

Full changelog since v7.x-1.8:

• #2652772 by DamienMcKenna: Fix update 7101 and rerun it to correct translation data.
• #2651812 by DamienMcKenna: Added an option to disable the i18n integration.
• #2420489 by Les Lim, DamienMcKenna: New caching process for entities.
• #2652260 by DamienMcKenna: Remove the revision_id from translation string IDs.
• #2509246 by DamienMcKenna, zniki.ru: Remove meta tags added by core, with option to leave them as-is.
• #2652294 by DamienMcKenna: Incorrect string context was being used for meta tag output translation.
• #2653434 by DamienMcKenna, reinchek: Fixed metatag_metatags_load().
• #2653446 by DamienMcKenna: Wrong variable name passed to metatag_config_delete().
• #1858540 by DamienMcKenna, friera: Added the pragma, cache-control and expires meta tags.