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/babl/template

@@ -3,7 +3,7 @@ pkgname=babl
 version=0.1.4
 revision=2
 distfiles="ftp://ftp.gimp.org/pub/babl/0.1/babl-${version}.tar.bz2"
-build_style=gnu_configure
+build_style=gnu-configure
 # XXX reenable when it's fixed.
 configure_args="--disable-introspection"
 short_desc="Dynamic pixel format translation library"