New utility program empdump

New utility program empdump

empdump exports and imports game state as plain text.  Limitations: it
currently can't export player bmaps, power report, telegrams,
announcements, message of the day, no-login message and log files.
Exported floating-point values may be inexact.  Importing an exported
game state may not result in identical data files; besides the loss of
floating-point precision just mentioned, coordinates are normalized,
and characters beyond a string's terminating zero in a character array
are lost.  Bug: importing resets timestamps to zero.  It should set
them to the current time.