PHPCS cleanup

Should all errors except in the DI package.

P.S. Whoever wrote the unit tests clearly didn't try that hard to meet the
standards :P
Fix up Google tests to run standalone
Remove filesystem functions with native PHP equivalents
Merge pull request #226 from dongilbert/GoogleTests

Fix up Google tests to run standalone
Review README files
Make Oauth Client class constructors have mandatory parameters.
Prep for beta3