Fix validation test

Applies these fixes:
 - Teaches validation test about blocks across different passes. Now, if
   a block was not optimal on a prior pass, the script knows it is not
   optimal in later passes.
 - Teaches validation test to handle dags with the same name. Many such
   examples exist in the benchmark suites that we use.

Additionally, a large number of commandline options have been added.

Author: Quincunx271