Now unit string supports regex, etc.
Improve testing result display.
Now testing result shows NaN, function, -0 and Infinity correctly.
Add `isnt` and `<>` operators for unit string.
Optimize some variable names.
Add a test.
Improve testing and fix bugs.
Adjust testing result display logic.
Add sha256 testing mark.
Add comments in test-test.
Testing supports nested variable definition.
Little adjustment.
Some tweaks.
Add some tests.
env now use "lookup from parent" instead of "populate child".
Now a test can be re-run.
Fix a display bug.
Fix two bugs.
Abandon "lookup from parent". Use a better mechanism.
$mate now superseded by npmMate.