Update the Elastic Data Processing (EDP) documentation page
Update the Elastic Data Processing (EDP) documentation page

* Add description of MapReduce.Streaming job type
* Add description of Spark job type
* Add reference to advanced configuration for Swfit proxy
* Note that .sahara suffix is added to Swift URLs automatically
* A few minor changes

Closes-Bug: 1374574
Closes-Bug: 1374606
Change-Id: Ie53888975ce436439cc808b2fdc45dff66bae1a9
(cherry picked from commit 7973db35e61b0c2d686798cb2de50d281713b03b)

keedio/sahara,openstack/sahara,mapr/sahara,zhujzhuo/Sahara,egafford/sahara,redhat-openstack/sahara,egafford/sahara,mapr/sahara,esikachev/scenario,henaras/sahara,mapr/sahara,ekasitk/sahara,crobby/sahara,zhujzhuo/Sahara,bigfootproject/sahara,zhujzhuo/Sahara,openstack/sahara,citrix-openstack-build/sahara,ekasitk/sahara,citrix-openstack-build/sahara,tellesnobrega/sahara,xme1226/sahara,esikachev/sahara-backup,matips/iosr-2015,zhangjunli177/sahara,bigfootproject/sahara,xme1226/sahara,crobby/sahara,esikachev/sahara-backup,henaras/sahara,henaras/sahara,tellesnobrega/sahara,xme1226/sahara,ekasitk/sahara,matips/iosr-2015,keedio/sahara,esikachev/scenario,esikachev/scenario,keedio/sahara,citrix-openstack-build/sahara,zhangjunli177/sahara,matips/iosr-2015,redhat-openstack/sahara,bigfootproject/sahara,zhangjunli177/sahara,redhat-openstack/sahara,crobby/sahara,esikachev/sahara-backup