Fix: Some fields of the renderer statistics were wrong.

Initialize them correctly so that they reflect the real minimum value encountered.

Thanks to Zener95.

This commit fixes #2939.
Blacklist Accusoft PICVideo M-JPEG Codec 2.1 since causes a DEP crash.

Newer versions of the decoder have a different CLSID and don't crash.
Cosmetics: add missing brackets and consistently use .0f instead of .f.
Some testing on SetAlwaysOnTop. (not working)