cumulative errors for session partitions;

proper guard for process_theory: ensure uniform precedence of results;

load HOL-Proofs first: it introduces some extra "thm" items that are required later on;

clarified count_file;

clarified modules;

more complete coverage of sessions: process_theory operation needs to handle duplicate theories;

proper build_graph to make session selection work as in "isabelle build";

incorporate sessions with record_proofs;

clarified options;

clarified signature;