New merge masters


per recent discussions, let's put a round of "merge master promotions"
in place:

   - Daniel and Justin become maintainers for BroControl and its

   - Johanna becomes a maintainer for Bro and submodules.

Daniel/Johanna/Justin: There are some guidelines on how to do merges

For reference, here's what our web page says about maintainers:

    Generally, all maintainers may merge any merge requests and
    fastpath commits. There’s no “must” however, everybody’s free to
    skip changes where they don’t feel sufficiently familiar with the
    corresponding code.

    For changes authored by maintainers themselves, we generally stick
    to the “two people rule”: maintainers do not merge their own
    patches, another maintainer has to do that. The exception is small
    straight-forward stuff, like simple bug fixes and cleanup. A good
    rule of thumb: if it’s a fastpath-suitable patch, direct commit
    into master without review is fine; if it’s a topic branch,
    consider filing a merge request for your fellow maintainers.
    However final decision is left to the discretion of the maintainer
    authoring the change.