Shared Library Changes for Release 3.0.2

Shared library libddcutil is backwardly compatible with the ones in ddcutil 2.2.1 and later. The SONAME is unchanged as libddcutil.so.5. The released library file is libddcutil.so.5.6.0.

This is an overview of changes in release 3.0.2 that are specific to the shared library. More detailed information can be found in file CHANGELOG.md in the source tree.

• AMDGPU disappears from PCI bus and freezes Plasma immediately after login. Issue 629.
• ddca_get_display_refs() and ddca_get_display_info_list2() could put a bogus message in the data returned by ddca_get_error_detail() even when the API calls succeeded.