micro-optimisation: format of log files

We should set the print environment when writing the log file entries (documents), to avoid using the pretty-printer and inserting newlines: We get:

(:HASH "C6A5609D-89F9-444D-BB59-47B1283AB1B6" :DELETED-P NIL :ELEMENTS                                                                                                                    
 (:RACE "Chinese" :GENDER "Male" :SURNAME "Brown" :NAME "Slave No 17" :EMP-NO                                                                                                             
  17))                                                                                                                                                                                                                                                                                                                                                                           

we should have:

(:HASH "C6A5609D-89F9-444D-BB59-47B1283AB1B6" :DELETED-P NIL :ELEMENTS (:RACE "Chinese" :GENDER "Male" :SURNAME "Brown" :NAME "Slave No 17" :EMP-NO 17))                                                                                                                                                                                                                                                                                                                                                                           

This is less pretty when opening the log files in an editor, but it'd be more efficient (no computing of column to insert newlines, no indenting (smaller records)) etc.