fixes #234: documenting requirements for running the tests as well as how to run them. also, making consistent apparent max 80-columns seen elsewhere in README.
fixes #234: documenting requirements for running the tests as well as how to run them. also, making consistent apparent max 80-columns seen elsewhere in README.

phonegap/phonegap-docs,phonegap/phonegap-docs,phonegap/phonegap-docs