Add product notes and payment_id #810

Add product_notes and payment_id to email template.
Add additional template tags & re-order

Re-order tags to match order in settings list.
Add full name, username and payment_id to template tags.
Add payment_id to list of template tags
Remove proudct_notes
Merge pull request #811 from elliott-stocks/patch-1

Fix #810 ,add additional template tags to email template