Remove the dependency on prettytable

Instead of pulling in yet another dependency for a mostly
debugging feature lets just have a tiny table object/class
that can work fine for our usage instead.

Part of blueprint top-level-types

Fixes bug 1368975

Change-Id: I21b1bd8152e5bf64b9060d3aabf4384350d05c0f
Merge "Remove the dependency on prettytable"