This came up on the mailing list.
yyyy-mm-dd (ISO 8601) is the internationally accepted format for numeric
dates. This commit changes all BIPs to use that instead of dd-mm-yyyy.
It also updates BIP 0001 to prescribe the new format.
- Mention github instead of wiki
- Add markdown as allowed format
- Fix some weirdnesses such as "A BIP editor must subscribe to the
gmaxwell@gmail.com list.". Remove the repetition and create a new
section which lists the BIP editors (currently only gmaxwell).
- Prefer discussion on mailing list to forum
