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/freeglut.tmpl

@@ -2,8 +2,8 @@
 pkgname=freeglut
 version=2.4.0
 patch_files="$pkgname-src-Makefile-in.diff"
-extract_sufx=".tar.gz"
-url=http://surfnet.dl.sourceforge.net/sourceforge/freeglut
+distfiles="
+http://surfnet.dl.sourceforge.net/sourceforge/freeglut/$pkgname-$version@.tar.gz"
 build_style=gnu_configure
 configure_args="--disable-warnings"
 make_cmd="$XBPS_MASTERDIR/bin/gmake"