Update Stripe Gateway Class (Customer Description)

If the order has a first/last name associated with it, use that,
otherwise, use the first/last name from the user meta.
Update Stripe Gateway Class (Customer Description)
Fixed bug where "Show Billing Fields" option for Stripe was sometimes hidden on the payment settings page.
hooks for adding column to table view

Added hook pmpro_discountcodes_extra_cols_header and pmpro_discountcodes_extra_cols_body to add new column to discountcodes admin page view
Update discountcodes.php
* Added hooks.
* Updated the expiration field dropdown on the edit levels page to use translation strings. (Thanks, 24uurdates)
Added the pmpro_member_startdate filter to filter the pmpro_getMemberStartdate function. Passes $user_id, and $level_id as parameters.
Added pmpro.getMembershipLevelForUser and pmpro.hasMembershipAccess XMLRPC methods. Example usage: https://gist.github.com/strangerstudios/9099164
Moved the Terms of Service page/etc to right above the checkout button.
* Now caching the pmpro_getAllLevels() function.
* Added HTML <!-- comment --> wrappers to the JS on checkout.php. Helps with validation and potentially really old browsers.
Fixed warnings in includes/login.php.
Merge remote-tracking branch 'upstream/dev' into dev