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/glitz.tmpl

@@ -2,7 +2,7 @@
 pkgname=glitz
 version=0.5.6
 distfiles="
-http://cairographics.org/snapshots/$pkgname-$version@.tar.gz"
+http://cairographics.org/snapshots/$pkgname-$version.tar.gz"
 build_style=gnu_configure
 configure_args="--with-x"
 pkgconfig_override="glitz.pc glitz-glx.pc"