prefer "fresh" open -- requires Lion / Mountain Lion;

clarified remove_overlay: always flush in order to make sure that apply_query can make a fresh start with the same arguments (see also 6e69f9ca8f1c) -- NB: print functions are idempotent;

prevent explosion in monomorphizer (e.g. when the facts typerep_int_def typerep_num_def typerep_option_def typerep_node_def are selected)

more parallelism in blocking mode

count remote threads as well when balancing CPU usage -- otherwise jEdit users and other users of the "blocking" mode may have to wait for 2 * timeout if they e.g. have 4 cores and 5 provers (the typical situation)

another shortcut alias;