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/python/template

@@ -5,7 +5,6 @@ revision=3
 patch_args="-Np1"
 wrksrc="Python-$version"
 distfiles="http://www.python.org/ftp/python/$version/Python-$version.tar.bz2"
-build_style=custom-install
 short_desc="Interpreted, interactive, object-oriented programming language"
 maintainer="Juan RP <xtraeme@gmail.com>"
 homepage="http://www.python.org"