Also fixed a bug that was exposed by the change (and removed some warnings)

prediction

pre-computed (instead of computing tons of pow() uselessly all the time)

do anything yet.

Code much leaner now.

"inverse" flag from the state so it can be shared between the forward and
inverse transforms.

used anywhere yet).

entropy coder. All testcases pass again.

with the entropy coder.

bitrate defaults.

Also, added an Ogg encoder (doesn't work quite yet).

(need to have test files installed otherwise it'll just pass by default)

especially now that we have a custom version of that code anyway. Moved
the test code to tests/