As suggested at https://mail.python.org/pipermail/python-committers/2015-September/003556.html, this is a draft patch for a new section in the developer guide that allows core contributors to declare our major financial interest (if any) in the core development process.

In addition to adding a paragraph suggesting new core developers consider filling in the register, I also rephrased the section regarding respecting people's time to reflect the fact that we're not all volunteers these days.

Based on the discussion in the python-committers thread, I made the disclosure of commercial interests potentially impacting Python's design & development the main aim of the register, with the creation of a public list of the core developers available for contract and consulting work as a positive side benefit.