Build system: Move template-based debian build into debian-template

We are going to want to introduce a real Debian source package build
system.  But that needs to contain a lot of things in debian/ which
ought not to appear in the .deb made by the existing ad-hoc `./build
debian' arrangements, which we want to keep so as not to unduly
disturb existing users.

So rename the whole debian/ directory to debian-template/ and change
all references in the build system.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

debian-template/wiringPi/DEBIAN/control

@@ -0,0 +1,10 @@
+Package: wiringpi
+Version: 2.24
+Section: libraries
+Priority: optional
+Architecture: armhf
+Depends: libc6
+Maintainer: Gordon Henderson <projects@drogon.net>
+Description: The wiringPi libraries, headers and gpio command
+  Libraries to allow GPIO access on a Raspberry Pi from C and C++
+  programs as well as from the command-line

debian-template/wiringPi/DEBIAN/postinst

@@ -0,0 +1,5 @@
+#!/bin/sh
+set -e
+/bin/chown root.root	/usr/bin/gpio
+/bin/chmod 4755		/usr/bin/gpio
+/sbin/ldconfig

debian-template/wiringPi/DEBIAN/postrm

@@ -0,0 +1,2 @@
+#!/bin/sh
+/sbin/ldconfig