1) fixed gng to last visited page upon error in login. Now saving
referer url in session
2) fixed openId auth registration form submission upon error in
registration
3) duplicate registration form submissions problem cannot occur as
captcha error is captured
4) changed message to "This email id is already registered" in case of
registering with same email id again
Merge branch 'biodiv_usergroups' of git@github.com:strandls/biodiv.git into biodiv_usergroups