libtheora: using the 1.0 API requires linking to both

libtheoraenc and libtheoradec; libtheora is the pre-1.0 library.
Documented at http://theora.org/doc/libtheora-1.0/
Fixes issue1564

Originally committed as revision 20588 to svn://svn.ffmpeg.org/ffmpeg/trunk

configure

@@ -2375,7 +2375,7 @@ enabled libopenjpeg && require libopenjpeg openjpeg.h opj_version -lopenjpeg
 enabled libschroedinger && add_cflags $(pkg-config --cflags schroedinger-1.0) &&
                            require libschroedinger schroedinger/schro.h schro_init $(pkg-config --libs schroedinger-1.0)
 enabled libspeex   && require  libspeex speex/speex.h speex_decoder_init -lspeex
-enabled libtheora  && require  libtheora theora/theoraenc.h th_info_init -ltheora -logg
+enabled libtheora  && require  libtheora theora/theoraenc.h th_info_init -ltheoraenc -ltheoradec -logg
 enabled libvorbis  && require  libvorbis vorbis/vorbisenc.h vorbis_info_init -lvorbisenc -lvorbis -logg
 enabled libx264    && require  libx264 x264.h x264_encoder_encode -lx264 -lm &&
                       { check_cpp_condition x264.h "X264_BUILD >= 78" ||