* rework net code for ip ranges to be cleaner
* clean up endpoint auth code
* refactor config to validate network configs before setting up endpoints
* remove buildone from path/pathbuilder.cpp so we don't spam connection attempts
- Move IPRange into its own net/ip_range.hpp
- Move the static net::IPPacket::TruncateV6, etc. functions to free
net::TruncateV6, etc. functions (now from net/ip.hpp instead of
net/ip_packet.hpp).
- Make net::TruncateV6 and net::ExpandV4 constexpr.
- Add IPRange::FromIPv4 factory function (to replace the iprange_ipv4
free function)
