Build-time activation of pkgstriptranslations

As of Ubuntu 5.10, pkgstriptranslations (which removes and collects translation data from packages during their build process) works in part through a patch to debhelper, as a means to arrange for it to be called at the proper time during the build process.

This is less than ideal, and gives Joey Hess one more thing to complain about in his blog.

We should investigate other ways of hooking into the build process which don't involve debhelper.