new operator about dflow

[fibo]

In the worst case I Will create a new0, new1, new2 .. functions to handle the arguments, in order to be able to use a 'new Foo(bar)' task that returns a 1arity constructor.

[fibo]

already implemented, there is also an example: it just need to be documented in examples list.

[fibo]

here it is: https://github.com/fibo/dflow/blob/master/src/examples/_start_here/newDate.js