clean up spamming 'have read' alerting when the user is spammy with interact

Author Daniel Pittman <daniel@rimspace.net>
Author date 2018-08-26 15:21:39
Author local date 2018-08-26 11:21:39 -0400
Committer Daniel Pittman <daniel@rimspace.net>
Committer date 2018-08-26 15:33:24
Committer local date 2018-08-26 11:33:24 -0400
Commit e680a252524b999582b4da2c5323570a47e20b21
Tree 550d07ad98fd85fc46127091ed83755d98fe0913
Parent 247f8e73b79278e2d77188d930c838e312b8291f
clean up spamming 'have read' alerting when the user is spammy with interact

Basically, suppress the text alert for three seconds after we show one, for
the same book.  We still beep and suppress display though, that all works as
it should.