generator-bat

feat(all generators): replace custom `determineRoot()` sub-generator functionality with the Yeoman default '.yo-rc.json' based one.

Let the app generator create a '.yo-rc.json' config file, containing a 'version' entry ' entry, designating the generator's version.
Sub-generators use the presence of this entry to assert whether they are running as part of a BAT app project.
Yeoman itself will take care of locating the project root.