Fixup broken unit test fallout.

Unit tests forced fleshing out the full coordinated scope of
cmdline specs and build_file_spec vs spec non-uniformity.
I killed build_file_spec and introduced extra handling in the
SpecParser to handle the typical command line uses natural
for users to use.  To make it clear SpecParser I renamed it
and added a unit test to check its addition handling over the
raw strict spec_parser.