createrelease: update copyright year script

The year is taken from the last commit that changed the file now rather
than current date. Also covers missed python scripts.

Author: wjakobsson

createrelease

@@ -45,7 +45,7 @@
 # cd ~/cppchecksolutions/cppcheck && python3 tools/get_checkers.py > lib/checkers.cpp
 #
 # Update copyright year: TODO release script
-# git diff $PREV -- */*.cpp */*.h | grep '^diff --git a/' | sed 's|.* b/||' | xargs sed -i "s/Copyright (C) 2007-20[12]./Copyright (C) 2007-$(date +%Y)/"
+# git grep -l 'Copyright (C) 2007-20' -- '*.cpp' '*.h' '*.py' | while read f; do y=$(git log -1 --format=%ad --date=format:%Y --invert-grep -i --grep=copyright -- "$f"); sed -i "s/Copyright (C) 2007-20[0-9][0-9]/Copyright (C) 2007-$y/" "$f"; done
 # git diff | grep '^diff --git a/'
 #
 # Make sure "cppcheck --errorlist" works: