Include MagicWand library in the dependency image. (#1209)

* Include MagicWand library.

* Remove duplication.

* Limit dynamic libraries in the release build.

* Use cp -a instead of -r.

* Use bash instead of sh.

dependencies/build_libraw.sh

@@ -1,5 +1,5 @@
-#!/bin/sh
-set -eu
+#!/bin/bash
+set -euo pipefail
 
 : ${DEB_HOST_MULTIARCH=`uname -m`-linux-gnu}
 : ${DEB_HOST_ARCH=`dpkg --print-architecture`}