Add RFC6265 cookie origin matching
Reject cookies with invalid origins being set
Only send matching origin cookies in requests
Add cookie origin tests
Ensure IRI object gets sent to formatForHeader
Use the correct variable for return URL
Check last character on cookie-path, not request
Normalize empty paths to /

In other words, undo the Requests_IRI normalization.
Add further tests for paths and domains
Add combined URL checks
iriMatches -> uriMatches
Check correct variable for domain normalization
Move normalization to instantiation
Move default-path normalization back

The normalization applied to the path should only be applied to the
default-path, not all paths.
Add tests for domains with leading period

This is part of the compatibility with older clients/servers as
specified in the RFC.
Merge pull request #120 from rmccue/cookie-origins

Restrict cookies to same-origin