RIP-1 (RFC 1058) support, ipaddress/netmask prefixes questions

[birdie at sigint.cs.purdue.edu]

According to the docs, RIP version 1 is not supported, but looking at
proto/rip/rip.c, it looks like it is.  Which is correct?

Also, the docs say that "ipaddress/netmask" (which I take to mean e.g.
10.0.1.0/255.255.255.0) is a valid form for prefixes, but filter/config.Y
doesn't appear to allow it.  (But hey, my yacc's pretty rusty.)

BTW, kudos to the BIRD team.  BIRD rains mucho guano on gated zebras.