fix documents.
fix reference information about paper of voice conversion.
fix source code, Makefile.am and Makefile.mak to compile vc command.
fix configure.ac to specify TARNAME explicitly.
fix Makefile.am for correct installation.
fix the problem of multiple definition of constant macros.
update all documents for version 3.7.
update all documents for version 3.7.
fix hyperlink for lspdf.
re-add constant semitone.