rethrow proposal and not-care construct

[Ruslan Shevchenko]

 Actually same as non-care without new keyword, can be emulated
(logically, not technikally) by rethrow extension as:

   catch Exception throw MyRuntimeWrapperException

It would be good to have some standard convention about exceptions, which
we belive impossible.

It can be UndeclaredThrowableException, or, may be create new standard
exception.