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
...until the definition is complete. This is necessary since sometimes
information outside the case block can help resolve interfaces, and in
the simplest case, we might just have delayed resolving a default
Integer. It turns out this was also an obscure bug waiting to happen
with coverage checking of nested case blocks (so there's a test update
there too).
Fixes#443
