2.4.0 - free trial support

This release adds proper support for free trials. Previously, developers could use user.installedAt to determine free trial eligibility, but that was vulnerable to users uninstalling and reinstalling the extension to get more free trial time.

Now, there is extpay.openTrialPage() and user.trialStartedAt which is populated after a user enters their email address and clicks a link in the email we send them.