Simplify logic
Fix whitespace and indent
Make add_hostname_to_watch return ips it's adding to later use
Add rc.newroutedns to change routes when hosts changes
Split system_routing_configure() and teach it to deal with hostnames
Use filterdns to update static routes using hostnames
Permit to use aliases containing hostnames on static routes
Last element is always empty, be sure we drop it
Add extra param, off by default, to make get_staticroutes() return hostnames too
Fixes to get routes + dns working:

. Simplify code using new parameter of get_staticroutes()
. Check for subnets instead of ip addrs
. Avoid touch filterdns when we are just updating dns
Fix whitespace