We have just released 8.2.1 of the v8-stable branch.
This release permits to build against json-c 0.12. Due to the ABI breckage, this is necessary. Json-c versions prior to 0.12 had security issues, so this is desirable. At least some distros have fixed the security issue in older versions of json-c, so this seems to apply mostly when building from sources.
Additionaly, the doc is no longer shipped as part of the rsyslog tarball to allow de-coupled release cycles.
As always, feedback is appreciated.