PBChangesource passwd code example is wrong

[joshua.clayton]

In at least the 0.8.5 and latest buildbot manual, Change source, PBChangesoure section http://buildbot.net/buildbot/docs/0.8.5/manual/cfg-changesources.html#chsrc-PBChangeSource there is a code example that reads:

from buildbot.changes import pb
c['changes'] = pb.PBChangeSource(port=9999, user='laura', password='fpga')

"password" should be "passwd"

Also (though less important) the whole section would be less confusing if passwd had its own very short entry instead of being listed as 'user and passwd', which makes it look like they are one kw. It was this confusion that led me to copy the code example in the first place.

[Dustin J. Mitchell]

fix up docs for PBChangeSource passwd parameter - fixes #2130

Changeset: 0ee4fe21f494caf8236941f6c964fada086801ce