bld_whitelist.conf consists of lines used by bld to configure
its white lists. The lines are processed in order of appearance. If two
lines contain different information about the same IP address, the last
is used. Blank lines and lines beginning with a `#' are ignored.
Lines have the following format:
`n.n.n.n' (IP address),
`n.n.n.n/m.m.m.m' (network with netmask)
or `n.n.n.n/b' (network with bitmask).
There is no need to restart or send any signal to bld after
modifying (or deleting) this file.