new ping observations

["rleong1" <rleong1@xxxxxxxxx>]

i've noticed it misses some heartbeats.  i have an xpl app and
floorplan bridges those heartbeats to xap.  i see the heartbeats in
both xap & xpl message viewers, but ping missed it.

also, jabber's heartbeats are rarely 60 seconds apart.  i've seen them
as much as 75 seconds apart but no closer than 67 seconds.  most other
xap apps i am using are very close if not exactly at 60 seconds.