Using autoconf we need a configuration file configure.in which contains the version number and other relevant information. See below for an example configure.in
Each of the identified AC_OUTPUT files will be generated by the configure script from the corresponding files suffixed with .in by the ./configure script which is in turn generated by the autoconf command which reads information from configure.in
So, when you change the version number regenerate the configure script with:
Next time you ./configure the new Makefiles and source code will contain the updated information.
The Makefile.in in the base directory includes a target to generate a tar file for distribution:
$ make dist
The resulting tar file will be named something like ./wajig-0.1.1.tar.gz. After making the distribution tar file move it to the parent directory for the convenience of the Debian packaging tools:
$ mv wajig-0.1.1.tar.gz ..