This makes things consistent with everywhere else we are incorporating the
new optional epoch field. Add a helper function that forms the version
string for you and use it in makepkg where I found 'pkgver.*-.*pkgrel'.
This exposes a few shortcomings in a previous "Override pkgver" patch
(2020e629) in the install package and check if built functions.
Signed-off-by: Dan McGee <dan@archlinux.org>