Three subcommands to this script:
1) ./copyright_header.py report
Examines git-tracked files with extensions that match:
INCLUDE = ['*.h', '*.cpp', '*.cc', '*.c', '*.py']
Helps to:
-> Identify source files without copyright
-> Identify source files added with something other than "The Bitcoin Core
developers" holder so we can be sure it is appropriate
-> Identify unintentional typos in the copyright line
2) ./copyright_header.py update
Replaces fix-copyright-headers.py. It does file editing in native python
rather than subprocessing out to perl as was the case with
fix-copyright-headers.py. It also shares code with the 'report' functions.
3) ./copyright_header.py insert
Inserts a copyright header into a source file with the proper format and
dates.
