RFC documents do not change over time. The custom org mode link handler
`db/org-rfc-open' now makes use of this by downloading RFC documents to
`db/rfc-cache-path' (if defined) and opening the files locally. If
`db/rfc-cache-path' is not defined, the RFC is opened in an external browser as
before.
This allows to keep a selection of used RFC documents locally on the filesystem
for future reference, without the need to retrieve them again from the IETF.
Since this is all org mode related, the handler now also resides in `db-org'
instead of `db-utils'.
Daniel -