Using the Ring CRDT and Weave gossip, provides an interface
for the weave script to allocate IP addresses in `weave run`,
`weave start` and `weave expose`.
See docs/ipam.md for implementation details, and site/features.md
for user-visible changes.
The weave SIGINT signal handler was racing the profiler SIGINT signal
handler. So now we a) make the former return instead of exit, and b)
disable the latter, as a result of which the deferred profile.Stop in
weaver/main gets called.
So as not to pollute command-line flags with test.* options.
It appears that importing "testing" (from stdlib) will add flags. To
avoid this, we need code to not depend on testing. But, since
testing_utils was previously in the same package as the rest of the
code, it dragged testing in.
Renaming testing_util.go to e.g., util_for_test.go might be enough to
avoid it being compiled with the regular code. We may want it to be
available to tests for other packages -- after all it is utilities for
testing -- so it goes in its own package.