Added AddArray project

The tutorial "Writer a very simple Network" wiki page describes the
implementation of a simple actor network.

http://orcc.sourceforge.net/tutorials/a-very-simple-network

This commit adds this completed project to the orc-apps repository,
and serves two purposes:

1. It can be linked to from the tutorial on the wiki.
2. It can be referenced in the in-progress "User Guide for HLS
   Backend" wiki page. See:
   https://github.com/orcc/orcc/issues/120#issuecomment-50617884
   https://github.com/orcc/orcc/wiki/User-Guide-for-HLS-Backend