Use bash features to improve $distfiles parsing.

That means that it's not necessary anymore to use an '@' before the
extract suffix string. yay.

--HG--
extra : convert_revision : 83ce2c783cb917ef59b87eacb0565cfcff277218

templates/firefox.tmpl

@@ -3,7 +3,7 @@ pkgname=firefox
 version=3.0.3
 wrksrc=mozilla
 distfiles="
-http://sunsite.rediris.es/pub/mozilla.org/firefox/releases/3.0.3/source/$pkgname-$version-source@.tar.bz2"
+http://sunsite.rediris.es/pub/mozilla.org/firefox/releases/3.0.3/source/$pkgname-$version-source.tar.bz2"
 build_style=gnu_configure
 configure_args="--enable-default-toolkit=cairo-gtk2 --disable-dbus
  --disable-crashreporter --enable-xft --with-pthreads --enable-xinerama