Gravity Forms User Registration Addon 5.3.0

- Fixed a fatal error which occurred if the GFFormDisplay class was not available when getting the login form HTML.
- Fixed an issue introduced in 3.9 which prevents the Pending Activations from being listed when the database tables are utf8 encoded instead of the newer utf8mb4.

- Added support for Gravity Forms 2.3.
- Added GPL to the plugin header.
- Added the "Preserve current email" choice to the email address mapping drop down on the update type feed.
- Updated URIs in plugin header to use https.
- Updated username validation message to match WordPress' equivalent validation message.
- Updated strings in pending activations so they could be translated
- Fixed an issue which can prevent pending activations from being listed due to collation mismatch after installing the add-on after upgrading MySQL from 5.5 to 5.6.
- Fixed a PHP warning related to the login form/widget logged in/out links.

- Added GPL to the plugin header
- Updated URIs in plugin header to use https
- Updated strings in pending activations so they could be translated