The Events Calendar Pro 6.4.0

* Feature - V2 Customizer - Add background color css overrides. [TEC-3651]
* Feature - V2 Customizer - Add Event Title color css overrides. [TEC-3334]
* Feature - V2 Customizer - Add Event Date & Time color css overrides. [TEC-3675]
* Language - 0 new strings added, 14 updated, 0 fuzzied, and 0 obsoleted

* Fix - Ensure we don't have pieces of Filter Bar present when using shortcodes. [ECP-527]
* Fix - Allow shortcode list widget to be redefined dynamically via a filter. [ECP-541]
* Fix - Use the Time Format defined in WordPress General Settings for Week View grid headers. [ECP-357]
* Tweak - Remove unused and the outdated `momentjs` library that was bundled with the plugin to use, in its place, the one bundled in The Events Calendar. [ECP-576]
* Language - 18 new strings added, 34 updated, 0 fuzzied, and 2 obsoleted

* Fix - Correct countdown widget so it show absolute time until event, irrespective of timezones. [ECP-146]
* Language - 0 new strings added, 1 updated, 0 fuzzied, and 0 obsoleted