Update bake project task.

It 'should' work once the cakephp/cakephp-app project becomes available.
Remove more dead code and add missing arguments to the composer command.
Remove subtree-split command.

We won't be subtree splitting every commit anymore. Instead the app
skeleton will become a standalone repository.
Add stub credentials to phpunit.xml.dist

This gives people a template to fill out, and gets them started with
SQLite.
Add README instructions for running tests & contributing.
Sort results in Folder::findRecursive test.

The results come out in a different order in different systems. Since
we're not testing the order the order doesn't matter.