WSD-203 #comment Added `returnto` value to OAuth2 `state` parameter.
`returnto` value is round-tripped through login flow, returned to the
Callback controller parsed and redirected to appropriate page.
Bypassing the login.do and directly taking user to Araport OAuth2
login page.
Redirect to originating page on failed login (refs WSD-161 WSD-203)

This workaround uses ActionForward() instead of mapping.findForward()
TODO: Implement this in a more elegant manner (using Struts standards)
Merge branch 'oauth2-support-stable' into stable

+ Disable interstitial Login page
+ Appropriately handle "returnto" parameter encoded in URL