Move some of the style in query.py one notch toward non-horribleness.
Rename _instance_path to _config_dir_path, because that's what it points to.

A DXR "instance" is the "target" folder.
Call a kwarg like it's a kwarg.
Make fully qualified member names trigger direct results. Fix bug 766122.

For some unknown reason, the % was at the front rather than at the back, where it's needed to eat the () or (params) which we jam into the qualname field along with the function name. (Type-signature overloading and all that jazz)

Also add a test for the other qualified-name direct-result case: types.
Stop using suffix matching for direct-result qualified-type queries.

This ought to make them much faster, as they'll be able to use the index (assuming the collation is case insensitive, which I'm not sure about). They're covered by the test I added in the previous commit. I've jazzed it up to check case-insensitivity, which may or may not be desired. For now, I'm playing it safe.
Disable autocomplete in the search field, because the autocompletion popup obscures the search results.