Remove plugin ordering for datamapper_rails.
Use :groups in place of deprecated :env in gem lines.
Make sure to run 'rails new' with --skip-test-unit.
Make sure all the testing gems are within groups.
Use Bundler to install gems; install them in vendor/.
Don't run rake tasks before installing gems.
Update the way we remove major components to work with Rails 4.

And don't try to configure components that we have removed.
Move database config file to example file, instead of copying it.