add new is_ub lemmas; clean up directed_finite proofs

new instance proofs for classes finite_po, chfin, flat

new lemma flat_less_iff

generalized chfindom_monofun2cont

Implemented proof of strong case analysis rule.

Added function fresh_const.

Added function partition_rules'.

another attempt to disable documents;

simplified position_props, always include line/file fields;

replaced thread_properties by simplified version in position.ML;

nested_command: simplified properties vs. position -- the latter also includes id now;

type T: based on properties, added id field; added thread_data, setmp_thread_data (formerly in toplevel.ML); tuned signature;

moved id to position properties;

instance unit :: finite_po

new axclass finite_po < finite, po

add lub_maximal lemmas; modify conclusion of directed_finiteD; declare not_directed_empty [simp]

added class Property: basic Isabelle properties;

tuned relevance test for presburger

output message properties: id or position;

toplevel print_exn: proper setmp_thread_properties;

added id property;

Result: added props field; tuned;

remove legacy ML bindings

new-style theorem references

fix theorem references

generalized and simplified proof of adm_Finite

new lemma adm_upward

Tuned (type information in Lemmas)