report the statements missing from the coverage.

--HG--
branch : pure-cffi
move away stale code

--HG--
branch : pure-cffi
more tests (stubs)

--HG--
branch : pure-cffi
pep8/pylint round.

--HG--
branch : pure-cffi
refactoring + coverage bump.

--HG--
branch : pure-cffi
Merge ../pyrana