Make `play new` consistent. Fixes #1927

* Make `play new` command require a parameter, the name of the project to create.
* If no parameter is given, the output now says "Use `play new foo` ..."
* It will not attempt to create something for `play new`
* Rewrite the detailedTopics/build/Build.md to adjust for this and provide more up-to-date, post 2.2 information.
* Adjust places in documentation where `play new` is mentioned.