Workaround source_root being the root directory of all projects in the subproject case. Remove now unneeded getpluginsdir and define c++ tests in the same loop. Bump meson requirement to 0.35
Workaround source_root being the root directory of all projects in the subproject case. Remove now unneeded getpluginsdir and define c++ tests in the same loop. Bump meson requirement to 0.35