#Feature-Add: Email Validation

[gtandersen]

List of signup related issues in process order:

• Decrease size of initial index sync modal that currently overlays the welcome offer: Decrease size of initial index sync modal #1509
• Ensure welcome email is visible in the Inbox upon signing up
• Clarify that the alternative email address must be validated on https://runbox.com/app/welcome?postSignup=offer (although an email is automatically sent to the submitted address)
• No indication on https://runbox.com/app/account/details or https://runbox.com/mail/account that the alternative email address has been validated
• No information or link to validate alternative email address from https://runbox.com/app/account/details
• The email validation link that is sent takes the user to Runbox 6 instead of 7
• Show a warning upon login if the alternative email address has not been validated

[castaway]

Patch to fix the welcome email issue submitted (to backend code)

[castaway]

See #1531 for item 1