Adaugare exercitii exception

Rezolvare exercitii de la sectiunena de exceptii din workshop-ul 1 (Java). Cerinte rezolvate sunt:
Exception handling:
1. Define a new exception.
2. Create a new example of throwing an exception by using you newly defined exception.
3. Create an example of exception propagation.
4. Create an example of nested exceptions in which the newly thrown exception.
5.  Create an example in which you make use of try/catch, try/catch with resources, try/catch/finally, try/finally and multi-catch.