Add script to update copyright years.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>

maint/utils/update-years.sh

@@ -0,0 +1,22 @@
+#! /bin/sh
+
+YEAR=`date +%Y`
+
+SOURCES="`find lib src tests -name '*.c'`"
+
+LINE="Copyright (C)"
+
+for i in "$SOURCES"; do
+    # replace year: XXXX-YYYY -> XXXX-ZZZZ
+    # add year: XXXX -> XXXX-ZZZZ
+    sed -i -e "
+        1,20 {
+                /$LINE/s/-[0-9]\{4\}$/-$YEAR/
+        };
+        1,20 {
+                /$LINE/s/ [0-9]\{4\}$/&-$YEAR/
+    }" $i
+done
+
+# special case
+sed -i -e "/$LINE/s/-[0-9]\{4\} the/-$YEAR the/" src/editor/editwidget.c