Add necessary path settings for tests in top-level tests/ directory
Add necessary path settings to use pocompile for test_mo.py
Skip search/indexing tests if no indexers are available
Skip these tests if we don't have iniparse
Skip if we don't have aeidon
Skip if we can't load cpo because "gettext PO library not found"
Escape &x0022 -> "

A non-roundtrip one
Decode » in DTD

Convert text to Unicode earlier so we can do the conversion correctly.
Install additional Mozilla related tools