Added a test for the from querystring parameter to ensure it is a relative address.
Added a test for the from querystring parameter to ensure it is a relative address.

This is protect the user against an open redirect attack.  See this
page for more details -
https://www.owasp.org/index.php/Top_10_2013-A10-Unvalidated_Redirects_an
d_Forwards

rmarji/keystone,brianjd/keystone,udp/keystone,unsworn/keystone,frontyard/keystone,matthieugayon/keystone,kloudsio/keystone,gcortese/keystone,benkroeger/keystone,rafmsou/keystone,DenisNeustroev/keystone,danielmahon/keystone,killerbobjr/keystone,belafontestudio/keystone,webteckie/keystone,davidbanham/keystone,lojack/keystone,beni55/keystone,joerter/keystone,BlakeRxxk/keystone,w01fgang/keystone,belafontestudio/keystone,andrewlinfoot/keystone,jrit/keystone,jacargentina/keystone,francesconero/keystone,alobodig/keystone,beni55/keystone,pr1ntr/keystone,douglasf/keystone,Yaska/keystone,Redmart/keystone,concoursbyappointment/keystoneRedux,kumo/keystone,Tangcuyu/keystone,lastjune/keystone,pswoodworth/keystone,youprofit/keystone,magalhas/keystone,qwales1/keystone,tomasztunik/keystone,jeffreypriebe/keystone,riyadhalnur/keystone,nickhsine/keystone,suryagh/keystone,unsworn/keystone,kidaa/keystone,andreufirefly/keystone,Adam14Four/keystone,ratecity/keystone,creynders/keystone,the1sky/keystone,danielmahon/keystone,stunjiturner/keystone,Adam14Four/keystone,vokal/keystone,mikaoelitiana/keystone,Pop-Code/keystone,BlakeRxxk/keystone,pswoodworth/keystone,vmkcom/keystone,ratecity/keystone,Pylipala/keystone,andrewlinfoot/keystone,omnibrain/keystone,Pop-Code/keystone,mbayfield/keystone,nickhsine/keystone,vokal/keystone,SlashmanX/keystone,kwangkim/keystone,antonj/keystone,matthewstyers/keystone,douglasf/keystone,everisARQ/keystone,antonj/keystone,tanbo800/keystone,trystant/keystone,xyzteam2016/keystone,sendyhalim/keystone,francesconero/keystone,codevlabs/keystone,sarriaroman/keystone,kittens/keystone,WingedToaster/keystone,efernandesng/keystone,kristianmandrup/keystone,jstockwin/keystone,onenorth/keystone,jacargentina/keystone,mbayfield/keystone,Ftonso/keystone,stosorio/keystone,pr1ntr/keystone,frontyard/keystone,jeffreypriebe/keystone,dvdcastro/keystone,riyadhalnur/keystone,stosorio/keystone,omnibrain/keystone,KZackery/keystone,davidbanham/keystone,47pages/keystone,magalhas/keystone,naustudio/keystone,Freakland/keystone,matthewstyers/keystone,onenorth/keystone,creynders/keystone,wilsonfletcher/keystone,gemscng/keystone,Freakland/keystone,webteckie/keystone,wmertens/keystone,wilsonfletcher/keystone,trentmillar/keystone,developer-prosenjit/keystone,TomKremer/keystonejs,dryna/keystone-twoje-urodziny,udp/keystone,sendyhalim/keystone,rafmsou/keystone,tony2cssc/keystone,benkroeger/keystone,w01fgang/keystone,WofloW/keystone,tomasztunik/keystone,snowkeeper/keystone,michaelerobertsjr/keystone,asifiqbal84/keystone,linhanyang/keystone,Yaska/keystone,wustxing/keystone,developer-prosenjit/keystone,efernandesng/keystone,youprofit/keystone,mekanics/keystone,geminiyellow/keystone,dvdcastro/keystone,danielmahon/keystone,ligson/keystone,dryna/keystone-twoje-urodziny,gcortese/keystone,sebmck/keystone,mekanics/keystone,the1sky/keystone,trentmillar/keystone,alobodig/keystone,ligson/keystone,wustxing/keystone,SJApps/keystone,naustudio/keystone,jrit/keystone,kumo/keystone,woody0907/keystone,qwales1/keystone,mikaoelitiana/keystone,SlashmanX/keystone,cermati/keystone,andreufirefly/keystone,SJApps/keystone,cermati/keystone,wmertens/keystone,Pylipala/keystone,akoesnan/keystone,davibe/keystone,Redmart/keystone,WingedToaster/keystone,ONode/keystone,frontyard/keystone,vmkcom/keystone,kloudsio/keystone,codevlabs/keystone,lastjune/keystone,DenisNeustroev/keystone,trystant/keystone,geminiyellow/keystone,benkroeger/keystone,kristianmandrup/keystone,gemscng/keystone,andrewlinfoot/keystone,chrisgornall/d29blog,joerter/keystone,woody0907/keystone,WofloW/keystone,trentmillar/keystone,sarriaroman/keystone,Ftonso/keystone,naustudio/keystone,vokal/keystone,snowkeeper/keystone,lojack/keystone,matthieugayon/keystone,brianjd/keystone,ONode/keystone,matthewstyers/keystone,MORE-HEALTH/keystone,MORE-HEALTH/keystone,quenktechnologies/keystone,michaelerobertsjr/keystone,tony2cssc/keystone,davibe/keystone,xyzteam2016/keystone,Tangcuyu/keystone,concoursbyappointment/keystoneRedux,kwangkim/keystone,stunjiturner/keystone,everisARQ/keystone,KZackery/keystone,kidaa/keystone,Yaska/keystone,asifiqbal84/keystone,chrisgornall/d29blog,akoesnan/keystone,tanbo800/keystone,suryagh/keystone,jstockwin/keystone