Convert rlm_cache to use map2request
Renumber FreeRADIUS-Client-Src-IP-Address and FreeRADIUS-Client-Src-IPv6-Address
Add Cache-Read-Only
Use the correct numbers in the dictionary files.

The attributes in the file are ordered for a reason, so that
typos like this can't happen.  Having random arrangements of
numbers makes it impossible to track what's going where