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/perl.tmpl

@@ -1,9 +1,8 @@
 # Template build file for 'perl'.
 pkgname=perl
 version=5.10.0
-patch_files="perl-dont-hardcode-rpath.diff"
-extract_sufx=".tar.gz"
-url=http://www.cpan.org/src
+patch_files="$pkgname-dont-hardcode-rpath.diff"
+distfiles="http://www.cpan.org/src/$pkgname-$version@.tar.gz"
 configure_script="Configure"
 configure_args="-Dusethreads -des -Dprefix=$XBPS_DESTDIR/$pkgname-$version
  -Ui_malloc -Uusemymalloc -Dinstallstyle=lib/perl5"