doing AgsAsyncQueue

Finally took decision to implement AgsAsyncQueue to achieve thread reliability. Assumed the object gives expected advantages ags will be soon released in its very first version 0.4.0

Due to strange crashes likewise crashing while returning true or corrupted double linked lists. This is all indicates thread safety related problems.

There was much time wasted with uncertainty but new courage has come not at least while reflecting and doing some forum posts.

There's much do left