This matches the convention used by opus itself, where
headers are included without a prefix, and the build
must do -I/path/to/opus to find the appropriate versions.

More consistent formatting, s/file/stream/g, and finish adding
 function warning attributes.

The actual problem was that opus-uninstalled.pc was forcing static
 linking, but not including all the relevant libraries.

This is needed to pick up -lm for libopus when it requires it.

Move this out of opusfile_example and into the API proper.

It's not actually used by the examples anymore.

Needed to build on my Fedora 16 machine.

This fixes the build to use the headers returned by pkg-config.
The opus library assumes the called will pass -I/path/to/opus
so #include <opus.h> will work.

It wasn't used, and version control has now preserved it forever,
 so no reason to keep it around.

It wasn't actually implemented.

Seeking and playback work, at least as far as the examples test
 them.
There are probably still lots of bugs.