Changes Introduced in 3#5

• New built-in open/4, enables opening files in binary mode.
• library(charsio): New predicate with_output_to_chars/4.
• library(heaps): New predicates delete_from_heap/4, empty_heap/1, is_heap/1.
• library(queues): New predicate is_queue/1.
• library(sockets): New predicates: socket_accept/3, and socket_select/6 provide address of connecting client. hostname_address/2 resolves name/ip-number.
• SP_atom_length returns the print name length of a Prolog atom.
• Modification time instead of current time stored for loaded files.