Exercise for Lecture 12: Virtual Proxy

Download, rebuild, and run the VS Document Solution.  Notice that the document reader downloads the entire textfile and formats all of it before you can read even the first formatted line.  For a long document, this will be frustrating.

Replace  class AllDoc  by  class VProxyDoc, a virtual proxy that builds formatted lines on demand.
(Write  class VProxyDoc  and change one line in  class Program.)

Now, the  Console App  calls the  VProxyDoc  for lines to display, and the  VProxyDoc  calls the  WordIterator  to fetch the words, one by one, from the input textfile.