Full release of oggedit

I partitioned the library so it links better.
The Vorbis and Flac plugins now call oggedit to write metadata, using padding when safe and useful.
Fixes issue #1102.
Workaround for issue #1116 in Vorbis, but only partially fixed.
Fixed issue #1119 in Vorbis.
Issue #1123 addressed sufficiently to be closed.
Oggstuff issues #1076, #1082, and #1104 are not fixed.
Maybe check the licenses are still suitable.  All the new code is new and written by me.  It links against Xiph shared libraries which I guess get pulled in to the static builds.