Update build_style for all templates.

- There's no need to set build_style for custom-install (default).
- gnu_{configure,makefile} renamed to gnu-{configure,makefile}.

srcpkgs/gst-plugins-base/template

@@ -3,7 +3,7 @@ pkgname=gst-plugins-base
 version=0.10.35
 revision=1
 distfiles="http://gstreamer.freedesktop.org/src/$pkgname/$pkgname-$version.tar.bz2"
-build_style=gnu_configure
+build_style=gnu-configure
 configure_args="--enable-experimental --disable-gnome_vfs
 --with-gudev --with-gtk=3.0 --disable-static"
 short_desc="Core GStreamer libraries and elements"