Improved EntrustTest

Improved EntrustTest.php.
Addresses issue #153. Improved to more closely match
the new tests in [Confide](https://github.com/Zizaco/confide).

In addition, committed git's auto-normalization of line 
endings to LF resulting from addition of .gitattributes in #165.
Also, added 3 fixes matching those in pending PR #166:
1. Entrust.php: $_app array access to $app prop access
2. git mv src/Zizaco/Entrust to src/Entrust
3. composer.json autoload to psr-4