browser2: Document why all this for handling cookies
browser2: Document why all this for handling cookies

sputnick-dev/weboob,frankrousseau/weboob,Boussadia/weboob,frankrousseau/weboob,laurent-george/weboob,willprice/weboob,RouxRC/weboob,willprice/weboob,Boussadia/weboob,sputnick-dev/weboob,sputnick-dev/weboob,yannrouillard/weboob,Boussadia/weboob,yannrouillard/weboob,Konubinix/weboob,nojhan/weboob-devel,frankrousseau/weboob,willprice/weboob,laurent-george/weboob,Boussadia/weboob,yannrouillard/weboob,RouxRC/weboob,Konubinix/weboob,Konubinix/weboob,laurent-george/weboob,nojhan/weboob-devel,RouxRC/weboob,nojhan/weboob-devel