Bug 1020457 - Merge webapi_tests package into the fxos-certsuite package

This is the remaining patch to get guided Web API tests running through run.sh and the meta harness.  Eventually semiauto will be split up into multiple modules and be moved to its own package which would simplify the imports.

The patch also fixes some other minor issues in certapp and the construction of some of the test classes.  It also moves the old MinimalTestCase based tests into webapi_tests/old to prevent any confusion.