future timestamps on image archives cause looping

Scribe items sometimes arrive from the field with original zip/tar's dated up to several days into the future. After making derivatives, the deriver starts all over again because it thinks the originals are newer than the derivatives, which recurs until the current time catches up to the postdated orig's.

Brewster suggested we clobber the problem by "touch"-ing the orig zip/tar's before deriving.

My proposal:

Intervene at line 295 of archive.php, where "$this->queueDerive()" happens. $scribe, treated as a boolean, tells us whether it's a book item, and the item directory and ID are available as $this->args['dir'] and $this->identifier. So if $scribe, touch any files in that directory that match <ID>_{orig,raw}_*.{tar,zip} and are dated in the future.

Raj has offered to do.