[base] TokenShaper: inherit timeout handler
added the ability to just run `make test` in order to run the tests.
[plugins] director: drop standby-role due to future changes rolling in.
be a little more greedy in time diff testing.

even on my laptop the test sometimes failed, possibly due to other tasks
running.
test time diff at last, since it's the most sensible one. ;)
some README updates wrt. Clang support
[base] TokenShaper: added missing namespace
[base] TokenShaper: do only propagate recomputing token capacities when the root node's capacity actually changed.