Now that cfgrep speed is vastly improved this test does not need
to be turned off as tedious.

Replace most of sed / grep calls with bash-native code.
Speed improved ~2x for basic tests and over 10x for games_with_spaces

Move to runner parameters -t and -s;  allow filtering based
on test name, sub-test name or both.

Add semantic exit functions and review exit statuses.

config.cfgrep does better job at hinting how the function works
(i.e. somehow similar to UNIX grep) and that the use is not limited to
INI files.

Also default config file suffix is now "conf".

 *  Add colors,
 *  print ffoo version,
 *  honor TF_DEBUG and TF_VERBOSE from environment,
 *  use nicer but smaller ASCII-art
 *  and include test name in subtest name.

"read strategy" is too ambiguous.  What is really happening is that we
are "merging" the (posible) files into one stream.

Now by default iniread will stop at first file; old behavior can be
restored by -j|--join switch.

Since it's normal e.g. for a dependency to import the same module as
upstream, the warning only created unnecessary noise.