Most changes are in tf_do_subtest.
* Separated setup/cleanup logic from test data collecting and
execution/evaluation.
* Revamped the execution/evaluation logic in a new tool testflt,
allowing tester to use it as the need be.
* Code to compose actual test command removed, as testflt makes it
easy to write the code in one place (TF_RUN) and keep simple things
simple.
* Removed tf_parse_meta, as it's obsolered by above changes.
* Updated tests to reflect the new style.
This new hierarchy makes it easier to work simultaneously on data and
the script, simplifies deployment to tempdir and makes the launching
script naming consistent with simple.sh.
Now testname.oracle file can specify expected exit status file
as well, or different path for stdout/stderr oracles (default is
testname.oracle.stdout and testname.oracle.stderr)
This effectively allows for testing scenarios where exit status or error
output can be tested as well.
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".