Ultimate Member - Social Login 2.5.6

* Added: Filter to allow automatic login with existing email address
* Fixed: Overflow forms in social register form
* Fixed: Duplicate welcome email
* Fixed: Session for custom role selection
* Fixed: Social authentication globally

* Fixed: WeChat Provider scopes
* Fixed: Minified scripts

* Added: WeChat Provider
* Added: Hooks for UM extensions integration
* Added: Allow form columns in Social Overlay
* Added: Hook to modify providers configuration
* Added: *.pot file for translations
* Changed: Google icon to match brand guidelines
* Fixed: Sanitation for role assignment with shortcode
* Fixed: Compatibility issue with plugins using OAuth
* Fixed: Redirection issue in child window