Adjust to new file layout.

Doc/tools/whichlibs

 #!/bin/sh
-sed -n 's/^\\input{\(lib[a-zA-Z0-9_]*\)}.*/\1.tex/p' lib.tex
+sed -n 's%^\\input{\(lib[a-zA-Z0-9_]*\)}.*%../lib/\1.tex%p' ../lib/lib.tex