WooCommerce API Manager 3.3.0

* Fix: Fixed "auth_key will be truncated by openssl_encrypt() since it is 64 bytes" warning.
* Fix: Fixed due to missing trailing slash at the end of directory name in autoload class, "Fatal error: Class 'WC_AM_Tools' not found in \wp-content\plugins\woocommerce-api-manager\includes\wc-am-core-functions.php on line 77."
* Tweak: Made some admin notices dismissible. Use new admin_notice CSS classes.

* WARNING: PHP 5.6 will no longer be supported after December 31, 2016. PHP: Supported Versions
* Dropped: Support for WooCommerce Subscriptions < 2.0 dropped.
* Refactor: Class objects are now autoloaded, so they are only loaded when needed, which results in less memory usage. Some code has been cleaned up and better formatted. Unused files and methods have been removed, and others have been moved to tidy up the directory and file structure.
* Update: Updated password.php used for older versions of PHP. Will be removed in a future version.
* Update: Replaced old encryption methods that used mcrypt(), which is slow and no longer maintained, with encryption methods that use openssl(). The result is increased speed and security.
* Fix: Switched subscription API Keys and API Downloads now display properly in the My Account dashboard.
* Fix: Prevent duplicate API Key generation on order when order status changed from Completed to another status, then back to Completed.
* Feature: Local secure download URLs expired after one click. Now those URLs will expire as set in Settings > URL Expire Time. Local secure download URLs will now work exactly the same as Amazon S3 URLs work.
* Feature: When a subscription expires, or is cancelled (not pending-cancellation), the subscription API Keys and API Key activations are deleted.
* Feature: When a subscription is switched, API Keys and API Key activations are deleted from the old parent and switched orders.
* Feature: Tabs displayed on Plugin Information screen, aka "View version details" screen, can now be turned on or off. Settings are located at WooCommerce > Settings > API Manager > API Doc Tabs.