Changes

Summary

1. updated package;
2. prefer immutable bindings;
3. tuned;
4. tuned;
5. updated to vscode-languageclient 3.0;
6. more thorough build;
7. clarified versions;
8. tuned;
9. clarified;
10. incremental document changes;
11. proper treatment of line that becomes empty;
12. tuned;
13. clarified Document.offset: including final position; support Document.change according to VSCode;
14. suppress vacuous edits;
15. clarified native Text.Offset versus Text.Length index Int;
16. tuned;
17. tuned;
18. tuned messages;