Revert "Updated prop mocking to not use __get() - I need to remember __get() forces array elements to be immutable (PITA)"

This reverts commit 1bad069ca8be60ac0de2332314ed62fa39f4f0e1.

Conflicts:
	library/Mockery/Generator.php
	library/Mockery/Mock.php
	tests/Mockery/ExpectationTest.php