configure.ac: use the 5-argument form of AC_INIT() and also define our own PACKAGE_DESCRIPTION
configure.ac: use the 5-argument form of AC_INIT() and also define our own PACKAGE_DESCRIPTION

lanniaoershi/protobuf-c,Sannis/protobuf-c,hongbinz/protobuf-c,y12uc231/protobuf-c,y12uc231/protobuf-c,lanniaoershi/protobuf-c,Sannis/protobuf-c,hongbinz/protobuf-c,tutu12777/protobuf-c,tutu12777/protobuf-c,koolhazz/protobuf-c,virqin/protobuf-c,y12uc231/protobuf-c,pepsi7959/protobuf-c,Sannis/protobuf-c,virqin/protobuf-c,lanniaoershi/protobuf-c,koolhazz/protobuf-c,pepsi7959/protobuf-c,pepsi7959/protobuf-c,koolhazz/protobuf-c,hongbinz/protobuf-c,tutu12777/protobuf-c,virqin/protobuf-c