remove code coverage for js dev files

I wanted to unit test private functions but it turned out to be
more pain than gain. As I splitted the code into several small
development files, the dependencies and paths started to become
difficult to manage.

It wasn't a good idea from the start so I think it's best to rollback.
add getPanelTitle test helper
add getPanelContent test helper
refactor loadPanel test helper to resolve when nothing moves

and update tests using it
refactor tests to test config through the public interface