Disable sd-event in release/v2.0 once #358 is merged and release/v2.0 rebased

[sangelovic]

          Beware, [`release/v2.0`](https://github.com/Kistler-Group/sdbus-cpp/tree/release/v2.0) contains 9cc74e9942a5 which isn't supported by either `basu` or ConsoleKit2 (sd-compat.c). `*SdEvent` API will have to be disabled on FreeBSD via `#ifndef SDBUS_basu` or similar.

Originally posted by @jbeich in #358 (comment)

[hellow554]

Hey @sangelovic

#358 is merged.

I was just about to open a new ticket upon the state of the release/v2.0 branch.
We use that branch in our code, because I needed that eventloop integration.

Meanwhile you're developing (awesome) stuff on the master branch, which isn't backported to v2.0

Is there really any advantage of having a 2.0 branch?

[sangelovic]

Hi @hellow554. Thanks for heads up. I've just rebased the release/v2.0 branch on top of master. (So make sure the update the commit hash if you're referencing any, since the history has changed.) Btw, the branch is meant as a long-living development branch for v2 features and changes, not yet officially as a release branch for production use. However, feel free to use it; you'll just have to update the commit hash from time to time when the release/v2.0 branch is rebased. The plan is that
the version v2.0 will be released officially once all currently planned work (and there is still v2-related work in the backlog to do) that has a breaking effect on the API/ABI/behavior has been finished on release/v2.0 and the branch has been merged to master, becoming the official main development line.