Gravity Perks (Gravity Wiz) 2.3.6

-Fixed issue where incorrect URL was used to check, activate and deactivate licenses.
-Fixed issue where announcements did not show up for non-English sites.

- Added GP_Plugin and GP_Feed_Plugin to integrate with Gravity Forms Add-on Framework.
- Added support for announcements; short banner messages with news and updates about Gravity Perks.
- Added support for new license types (Basic, Advanced, Pro).
- Added license toolbar on Manager Perks page.
- Added GRAVITY_PERKS_VERSION constant for managing plugin version.
- Fixed a myriad of notices.
- Removed a myriad of unused legacy code.
- Removed settings page.

- Replaced Markdown library to resolve several PHP errors.