Email-to-a-friend page (share)

[phillipadsmith]

• Update to https://github.com/phillipadsmith/share.thetyee.ca (and migrate to The Tyee) to point to https://github.com/TheTyee/webhook.thetyee.ca-subscribe

[phillipadsmith]

• Check that $wc_sub_pref indicates a subscription request
• Send the request to webhook.thetyee.ca/subscribe for processing
• On success, set the wc_status to 1
• wc_result_sub to $sub_id || 'None requested'

[phillipadsmith]

I'm backtracking now because each add_to_whatcounts script contains data processing that is specific to that type of subscription event, e.g., sharing, becoming a supporter, taking a survey.