(Binary Analysis) Better support for producing GraphViz files

* <Partitioner2/GraphViz.h> has an API for creating GraphViz dot
  files. It supports CFGs and CGs that are part of the Partitioner
  data structures.  Old-style CFGs and CGs are still produced
  by the BinaryControlFlow and BinaryCallGraph APIs but do not
  contain as much information as the new stuff.

* The recursiveDisassemble tool has a number of new command-line
  switches for producing GraphViz files. See --help for details.