run-tests: don't need to test shebang any more
run-tests: make a table of test types
run-tests: filter out non-tests from default list
tests: simplify handling of unknown test types
run-tests: pull hgrc creation out as function
run-tests: regroup temp dir creation
run-tests: regroup nested functions
run-tests: regroup some variable initialization
run-tests: fix a path existence check
run-tests: regroup some initialization checks
run-tests: change return code of runone
run-tests: unify marks and result codes
run-tests: make vlog a proper function
run-tests: add a log function
run-tests: remove some unnecessary globals