[Reviewer: Matt][From: Alex] Update stats tools to cope with homestead stats.

Matt, please can you review this change. IT covers:
* Modifying the tools to recognize the homestead(-prov) stat names.
* Extending them to deal with some stats being available on 6667. 
  * For the cpp tool this just involves mapping the stat name to the port. 
  * For the ruby tool in "all stats" mode the user can specify which ports to pull from.

Tested as follows:
* Use the cpp tool to pull individual stats from bono, sprout, homestead, homestead-prov and homer. 
* Ditto for the ruby tool. 
* For the ruby tool in "all stats" mode:
  * Pull stats from sprout (no port specified). Gets all sprout stats. 
  * Pull from homestead (no port specified). Gets H_* stats. 
  * Pull from homestead (-p 6666,6667). Gets H_* and P_* stats.
  * Pull from homestead (-p 6667). Gets P_* stats.
  * Pull from homer (-p 6667). Gets P_* stats.