v1.x-1.2.0

Feature, maintenance and bugfix release.

Note: You'll be prompted to run the update script.

• Issue #58: Update TinyMCE to version 6.8.2 by @indigoxela in #62
• Issue #63: Allow themes to provide css files for content_css by @indigoxela in #64
• Issue #60: Add custom list property context menu by @indigoxela in #61
• Issue #65: Switch plugins to IIFE by @indigoxela in #66
• Issue #59: Profile builder and screen readers and keyboard nav by @indigoxela in #67

Full Changelog: 1.x-1.1.1...1.x-1.2.0