makepkg will now error if disallowed variables are set inside of
the package function.
Disallowed variables are variables that do exist, like 'makedepends'
and 'pkgver' but can not be set inside of a package function.
Signed-off-by: morganamilo <morganamilo@gmail.com>
Signed-off-by: Allan McRae <allan@archlinux.org>