Maintain redirect options in session. Fix #221

To reflect redirect_to options, keep redirect url in session to be set
'X-XHR-Current-Location' in response header.
Use X-XHR-Redirected-To instead of X-XHR-Current-Location

Set redirect location to X-XHR-Redirected-To header
only when server redirects user.
And use the location info in reflectRedirectedUrl.
Merge pull request #222 from YasuOza/keep_anchor_on_redirect

Maintain redirect options in session. Fix #221
Reflect changes from PR #222
Escape URLs when checking for cross-origin redirects