Major changes to support multiple distfiles in templates.

Each template now needs to use $distfiles that accepts the full
URL to download the distfile and old $extract_sufx is now merged
on it, but this must be separated by the '@' character. Example:

distfiles="http://www.foo.org/blah-6.2@.tar.gz
http://www.foo.org/blob-1.0@.tar.bz2"

If distfiles contains multiple files defined, $wrksrc is now
mandatory.

--HG--
extra : convert_revision : 1c3fa35f148af8323ce3cbcf5732104960de6bc4

templates/sudo.tmpl

@@ -2,8 +2,7 @@
 pkgname=sudo
 version=1.6.9p17
 patch_files="$pkgname-Makefile-in.diff"
-extract_sufx=".tar.gz"
-url=http://www.courtesan.com/sudo/dist
+distfiles="http://www.courtesan.com/sudo/dist/$pkgname-$version@.tar.gz"
 build_style=gnu_configure
 configure_args="--disable-root-mailer"
 short_desc="Allow others to run commands as root"