Fix read not to split production report when update is slow

Fix read not to split production report when update is slow

Adjacent telegrams are squashed together if type and sender are the
same, and the timestamp is "close enough".  This is done in two
places: rea() and typed_wu().  They're inconsistent: typed_wu()
ignores the timestamp for production reports since Empire 2, but rea()
doesn't.

Record typed_wu()'s decision in new telstr member tel_cont.  Use it in
rea().