While the discussion about how to refactor test framework is not
finished (#1654), make this change: move `rm -rf build` in the
beginning of the test. For these reasons:
* it is useful to inspect the contents of the `build` directory
especially after the test failure
* if build crashes mid-test (e.g. process killed), next run should
not be affected by the `build` directory from the previous run
- Added initial implementations for terms and values
- Error messages converted to pretty printer
- Colorization for error messages
- Color and console width option both as command line and repl command
This is quite fiddly as it the blocks might be in different contexts so
we need to keep track of which variables correspond in the scrutinees of
the blocks. Once that's done, check the terms at the leaves convert,
then check the corresponding variables convert.
This may not be perfect yet, because we only look at case scrutinees to
find correspondence. It might also be a bit slower than it could be, but
at least these checks are quite rare.
Fixes#208 and maybe some others?
