Change <T> T get(String key) to allow direct Casting.

[alorma]

This will make a ClassCastException if you pass an Object type that is not correct.

[rocboronat]

Wep! Just realized that the code that tests that the casting is OK and the casting is bad is different.

To test that it breaks:
ObjectTestTwo testTwo = (ObjectTestTwo) cache.get(A_KEY);

To test that it's OK:
ObjectTestOne objectTestOne = cache.get(A_KEY);

Can we test the two ways to get an OK and a KO?

[rocboronat]

Yep! I'll do it :·P