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/libidn.tmpl

@@ -1,8 +1,7 @@
 # Template file for 'libidn'
 pkgname=libidn
 version=1.10
-extract_sufx=".tar.gz"
-url=http://ftp.gnu.org/gnu/libidn
+distfiles="http://ftp.gnu.org/gnu/libidn/$pkgname-$version@.tar.gz"
 build_style=gnu_configure
 pkgconfig_override="libidn.pc"
 configure_env="EMACS=/bin/false"