Add helper script for generating online documentation
Add helper script for generating online documentation

If build-aux/generate-docs is run from the top level of the checkout,
it will prompt for the old and new version numbers, and generate
doxygen, ABI compatibility and change log documentation,
and commit them to the gh-pages branch.

ClusterLabs/libqb,kgaillot/libqb,ClusterLabs/libqb,ClusterLabs/libqb,kgaillot/libqb,kgaillot/libqb