standardize the default shell

I do not know of a need to have the default shell be a build-time
configurable setting. All *nix systems I am aware of have /bin/sh as a
default posix compatible shell.
If some systems running OpenRC do not make that assumption about
/bin/sh, I will consider bringing this back, so feel free to open an
issue.

sh/binfmt.sh.in

@@ -1,4 +1,4 @@
-#!@SHELL@
+#!/bin/sh
 # This is a reimplementation of the systemd binfmt.d code to register
 # misc binary formats with the kernel.
 #

sh/cgroup-release-agent.sh.in

@@ -1,4 +1,4 @@
-#!@SHELL@
+#!/bin/sh
 # This is run by the kernel after the last task is removed from a
 # control group in the openrc hierarchy.
 

sh/gendepends.sh.in

@@ -1,4 +1,4 @@
-#!@SHELL@
+#!/bin/sh
 # Shell wrapper to list our dependencies
 
 # Copyright (c) 2007-2015 The OpenRC Authors.

sh/init-early.sh.Linux.in

@@ -1,4 +1,4 @@
-#!@SHELL@
+#!/bin/sh
 # Copyright (c) 2007-2015 The OpenRC Authors.
 # See the Authors file at the top-level directory of this distribution and
 # https://github.com/OpenRC/openrc/blob/master/AUTHORS

sh/init.sh.BSD.in

@@ -1,4 +1,4 @@
-#!@SHELL@
+#!/bin/sh
 # Copyright (c) 2007-2015 The OpenRC Authors.
 # See the Authors file at the top-level directory of this distribution and
 # https://github.com/OpenRC/openrc/blob/master/AUTHORS

sh/init.sh.GNU-kFreeBSD.in

@@ -1,4 +1,4 @@
-#!@SHELL@
+#!/bin/sh
 # Copyright (c) 2007-2015 The OpenRC Authors.
 # See the Authors file at the top-level directory of this distribution and
 # https://github.com/OpenRC/openrc/blob/master/AUTHORS

sh/init.sh.GNU.in

@@ -1,4 +1,4 @@
-#!@SHELL@
+#!/bin/sh
 # Copyright (c) 2007-2015 The OpenRC Authors.
 # See the Authors file at the top-level directory of this distribution and
 # https://github.com/OpenRC/openrc/blob/master/AUTHORS

sh/init.sh.Linux.in

@@ -1,4 +1,4 @@
-#!@SHELL@
+#!/bin/sh
 # Copyright (c) 1999-2007 Gentoo Foundation
 # Copyright (c) 2007-2009 Roy Marples <roy@marples.name>
 # Released under the 2-clause BSD license.

sh/migrate-to-run.sh.in

@@ -1,4 +1,4 @@
-#!@SHELL@
+#!/bin/sh
 # Copyright (c) 2012-2015 The OpenRC Authors.
 # See the Authors file at the top-level directory of this distribution and
 # https://github.com/OpenRC/openrc/blob/master/AUTHORS

sh/openrc-run.sh.in

@@ -1,4 +1,4 @@
-#!@SHELL@
+#!/bin/sh
 # Shell wrapper for openrc-run
 
 # Copyright (c) 2007-2015 The OpenRC Authors.