more informative known_files: known_theories within the local session directory come first; more thorough Session.Base.platform_path;

less global theories -- conflict with AFP entries;

support for known theories files (according to multiple uses);

proper display_name;

clarified theory_long_name (for qualified access to Thy_Info) vs. short theory_name (which is unique within any given theory context);

tuned signature;

proper import qualifier for global theories; clarified uniqueness;

explicit theory qualifier for session "HOL-Proofs": its theory name space overlaps with session "HOL", even for further imports;

proper qualifier for imports;

clarified, according to Scala version;

tuned text;

clarified signature;