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/expat.tmpl

@@ -1,8 +1,8 @@
 # Template file for 'expat'
 pkgname=expat
 version=2.0.1
-extract_sufx=".tar.gz"
-url=http://kent.dl.sourceforge.net/sourceforge/expat
+distfiles="
+http://kent.dl.sourceforge.net/sourceforge/expat/$pkgname-$version@.tar.gz"
 build_style=gnu_configure
 short_desc="XML parser library written in C"
 maintainer="Juan RP <xtraeme@gmail.com>"