A long time ago, wave used to be really hard to navigate.
Real-time apps really need good navigation, the fact wave
is tree-based, and not distinctly linear complicates things
even moreso.

I never use gmail, nobody ever emails me (i don't know why,
honestly, i don't even get that much spam even though my email
is like totally out-there, so here's one more opportunity for
spambots to harvest my email which is antimatter15@gmail.com
and if the bots have developed reverse psychology and only parse
emails in the format of a pseudo-anti-spambot format of 
antimatter15 [at] gmail [dot] com it's there too). So if you're
reading this, I wouldn't mind a random email.

Anyway, back on topic, uh, i like gmail's little thready arrows
thingy. Though I'm not sure what it's supposed to do as it's not
necessarily read-state sensitive half the time, and email really
doesnt need arrows for that so much as it's really pretty linear 
anyway.

So i felt it would be useful in google wave and so I did it.

Nowadays, there's the native [(3) Next] button which mostly
obsoletes this functionality and I believe it probably wont 
work anyway because of the new lazy-loading features.

It includes a little class-detection engine via styles, but 
that doesnt really matter.

https://chrome.google.com/extensions/detail/jncflgepcddhcejhofdojlkjgjhcfmpc