Unify run scripts
Add xip serval

Although this first version prints out all local sockets (i.e.
ServiceIDs, FlowIDs, and request sockets), it does not support
route redirects.
Generalize routing redirects

XIA kernel has generalized routing redirects for principals, thus
it's a natural step to generalize its handling in application xip
as well.

As a bonus, support for routing redirects is added to xip serval.
Update howto and xip/TODO