Updated git repository names
Modified artifact name
Renamed/Moved all spring3 artifacts to spring4
Moved version back to 2.1.2-SNAPSHOT
Modified basic documentation artifacts spring3 -> spring4
Added minor note to README
Adapted code to Spring 4's version of RequestDataValueProcessor
Adapted code to Spring 4's version of RequestDataValueProcessor
Merge branch '2.1-spring4-dev' into 2.1-spring4-master