[opus] Unknown versions in git.

[Timothy B. Terriberry]

bat guano wrote:
> (look for the CURRENT_VERSION definition).
>
> CURRENT_VERSION
>
> Search string not found 		 	   		

configure.ac:3
dnl The package_version file will be automatically synced to the git 
revision
dnl by the update_version script when configured in the repository, but will
dnl remain constant in tarball releases unless it is manually edited.
m4_define([CURRENT_VERSION],
           m4_esyscmd([ ./update_version 2>/dev/null || true
                        if test -e package_version; then
                            . ./package_version
                            printf "$PACKAGE_VERSION"
                        else
                            printf "unknown"
                        fi ]))