[Click] gaprate has startup bug

[Bart Braem]

Hello,

I've been busy investigating why ratedsplitter always drops the first packet. 
Here's why:
- ratedsplitter uses _rate.set_rate (with error handler argument) in its 
configure
- after a check on too large rates set_rate calls its own set_rate (without 
error handler argument) which calls reset at the end
- one of the things reset does is setting _tv_sec to -1
- next the first packet arrives at ratedsplitter, that calls need_update
- need_update check checks wether _tv_sec is negative and so sets sec_count to 
((now.tv_usec << UGAP_SHIFT) / _ugap) + 1
- unsigned need is set to ((now.tv_usec << UGAP_SHIFT) / _ugap)
(that last one always turns out to be 0 in my simulations!)
- the result of need_update is: (int)need >= sec_count
- that's not true, so ratedsplitter pushes on port 1, so first packet is 
dropped...

My guess is that somewhere the unsigned-signed conversion doesn't do its job. 
Mainly because otherwise need would always be smaller than _sec_count...
Does someone know more about this piece of the code? Or should I just abondon 
it?

Bart