Restructure test folders to separate test/oracle/result
Support test folder structure where test, oracle and generated result
data are stored each in separate directory. This makes it easier to
ensure legible diff output without cluttering the filenames too much.
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.