[copyright] add MIT license headers to .sh scripts where missing

Years are set according to 'git log' history

Github-Pull: #8700
Rebased-From: 0766d1cac38d7ea27a6323d7ca206154b2686f9b

src/qt/res/movies/makespinner.sh

@@ -1,3 +1,7 @@
+# Copyright (c) 2014-2015 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
 FRAMEDIR=$(dirname $0)
 for i in {0..35}
 do