Remove: performance measurements in YAPF

YAPF was constantly measuring its performance, but only at
certain debug-levels this information was shown.

Now after years, I sincerely wonder if anyone still knows about this
feature and who still use it. Especially with the new framerate window,
this detailed performance is not as meaningful anymore as it once
was.

(svn r18481) -Codechange: unify the curve pathfinder penalty defaults; 0.01 tile won't make a dent, 3 tiles might be a bit too much
-Feature-ish: make maximum pathfinder penalties for finding depots customisable, also increase it slightly to 20 tiles worth of penalties.