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/parted/template

@@ -2,7 +2,7 @@
 pkgname=parted
 version=2.4
 distfiles="http://ftp.gnu.org/gnu/parted/parted-$version.tar.xz"
-build_style=gnu_configure
+build_style=gnu-configure
 configure_args="--without-included-regex --with-gnu-ld
 --disable-rpath --disable-debug"
 short_desc="The GNU Parted disk partition resizing program"