Add SPDX-License-Identifier headers

Add SPDX-License-Identifier headers to all substantial source files.
Collapse copyright years.  Add some Emacs configuration for files
where the copyright notice is at the end.  Add a test that every
file has SPDX-License-Identifier.

1 files changed, 3 insertions, 0 deletions

diff --git a/contrib/commerzbank/wallet-history b/contrib/commerzbank/wallet-history
index 9826057..0adc766 100755
--- a/contrib/commerzbank/wallet-history
+++ b/contrib/commerzbank/wallet-history
@@ -31,6 +31,9 @@
 # perl wallet-history.pl ... (t.b.d.)...
 #
 #--------------------------------------------------------------------------------------------------------------
+#
+# SPDX-License-Identifier: MIT
+
 # Version.
 
 my $VERSION = "0.5";