Adjust the plugin to use the socket C-API found under
dde_linux/src/lib/lxip/include/genode_c_api/socket.h'.
This is the first minor step in generalizing the plugin.
isse #5104
This is a follow-up commit to "Increase default warning level", which
overrides Genode's new default warning level for targets contained in
higher-level repositories. By explicitly whitelisting all those targets,
we can selectively adjust them to the new strictness over time - by
looking out for 'CC_CXX_WARN_STRICT' in the target description files.
Issue #465
