Fix semantic error handling bugs

- Associate error codes with correct error domains
- Remove deprecated gerrorf macros
- Add ccl_arg_full macro (which calls ccl_arg_new), such that
clients don't call a _new function for something they will not
destroy + remove ccl_arg_* functions from public API docs (only
the macros should be used by clients)
- Devinfo: fix default platform information in case of error