Clarify what libfaadbin means in the summary output.

Originally committed as revision 9448 to svn://svn.ffmpeg.org/ffmpeg/trunk

configure

@@ -1836,7 +1836,7 @@ echo "libamr-nb support         ${libamr_nb-no}"
 echo "libamr-wb support         ${libamr_wb-no}"
 echo "libfaac enabled           ${libfaac-no}"
 echo "libfaad enabled           ${libfaad-no}"
-echo "faadbin enabled           ${libfaadbin-no}"
+echo "libfaad dlopened          ${libfaadbin-no}"
 echo "libgsm enabled            ${libgsm-no}"
 echo "libmp3lame enabled        ${libmp3lame-no}"
 echo "libnut enabled            ${libnut-no}"