* Emit warning for fixities with no export modifiers
This is to help update all the existing code to program with explicit
fixity export directives in preparation for the behavioral change where
they will become private by default.
* [ fix ] semantic highlighting in IDE mode
Bring back (?) highlighting of goals
* [ debug ] better logging: add length
* [ test ] turns out lengths are not needed!
Even though the `Comment` aspect is not (currently) supported
in the IDEMode, this is crucial to get proper highlighting in
Katla's LaTeX & HTML backends.
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
