Contact Form Text Widget: Contact Form URL field is not referral URL

# Issue

The "Contact Form URL" field received in the email is incorrect. You would expect to receive the referral URL.
# Steps to reproduce:
1. Insert a text widget into your widget area.
2. Visit a page (eg: http://blog.example.co.uk/about/)
3. Fill out and submit the form
# Actual:

Your Name: James Wade
Your Email: jw@example.co.uk
Enquiry Type: Test

Time: October 10, 2014 at 2:45 pm
IP Address: 123.123.123.123
Contact Form URL: http://blog.example.co.uk/
# Expected:

Your Name: James Wade
Your Email: jw@example.co.uk
Enquiry Type: Test

Time: October 10, 2014 at 2:45 pm
IP Address: 123.123.123.123
Contact Form URL: http://blog.example.co.uk/about/

No file or test is named in the issue. Start by reproducing the Contact Form text widget submission from a page with a path and trace where the Contact Form URL email value is assembled; done means the email contains the full referral URL, such as /about/, rather than the site root.

Written by the indexing model from the issue text.