Processes: Fix <= 9.1 to show only db related processes & clean dbname.

Fix bugs introduced in commit d571ecae7b by ioguix on 2012-09-21.

I can't tell why these changes crept in along with the rest of
the fixes in that commit.  It looks like a testing version was
committed.
Fix so signals are sent to the right pid.
Add support for user-sent signals. (9.2+)
Make process screen report information in a way that makes sense in postgres 9.2
Also add in the waiting option, making it work back to at least 8.1
doTree() does not take an argument.