Streaming parsers in D a novel design

[Dmitry Olshansky]

A streaming parser is doing 2 things:
- waiting for input
- processing the current input and spitting out Events

This maps to D beautifully:

1. Waiting for input means it's an OutputRange with explicit put 
method!

2. Processing events means it's an InputRange of events. It may 
even be ForwardRange, mine first of this kind is Forward range.

Destroy!

--
Olshansky Dmitry