Remove pointless -working flag.

This option is not needed. The new working directory is always set to
the application's ROOT directory.
Add info about how to exit console shell.
Update windows batch file.
Remove -q.

It doesn't work and breaks HHVM.
Merge pull request #48 from cakephp/shell-cleanup

Shell cleanup
Merge branch 'master' of https://github.com/cakephp/app
Move to plugin