Consider bumping the version number to something never used in old ytnef

[jmallach]

Hi Yeraze,

When I submitted the patch that unified lib and tools into the same autotools tree, it was merged before we had the chance to discuss the version, and it ended inheriting the one from the lib's configure.ac. At the same time, the package was renamed to ytnef.

Debian and other distributions have probably shipped the tools-only version of ytnef with version 2.x, which means it is probably at some point the same source name and version might be reused. This will be ugly in Debian at least as the archive software still remembers and always will that it once shipped an ytnef 2.6 with a given file checksum, etc.

I suggest you artificially bump the version number to 2.9 (the latest version of ytnef configure.ac had 2.8) or 3.0 or whatever so we skip any possible problem in the future.