Festival provides a C++ and C api for which it would be nice to have a
pkg-config file.  I've attached two template files for festival when it
is installed and uninstalled.  I tried to also come up with a patch to
have them be in installed as part of the package, but had difficulty
understanding the build system, as it seems to be a mixture of autotools
and custom makefiles, and the debian package seems to add a layer on top
of that.

One thing I should note is that I don't think festival provides the
PACKAGE_VERSION to autoconf, so that might have to be manually entered
into the template.  Also, it depends on estools, which also would need a
pkg-config file.