contrib/devtools/fix-copyright-headers.py script to be able to perform this maintenance task with ease during the rest of the year, every year. Modifications to contrib/devtools/README.md to document what fix-copyright-headers.py does.
After the tinyformat switch sprintf() family functions support passing
actual std::string objects.
Remove unnecessary c_str calls (236 of them) in logging and formatting.
`getinfo` is a general info method which shows information
from multiple sources, it doesn't belong in rpcnet.cpp or
any of the other current RPC implementation files.