Switch back some optimistic functions in tools/fs/watch.js.
Switch back some optimistic functions in tools/fs/watch.js.

In particular, optimisticReaddir was getting called before relevant dirty
callbacks were firing, and thus failing to notice actual changes on the
file system.

In general, the tools/fs/watch.js code is the one place where we really
need an up-to-date view of the file system. Put another way, if optimistic
functions worked perfectly, we wouldn't need to rely so much on WatchSet
logic, but for now it's a balance of equally important strategies, and we
shouldn't be compromising one by intermingling it with the other.

mjmasn/meteor,Hansoft/meteor,Hansoft/meteor,Hansoft/meteor,mjmasn/meteor,mjmasn/meteor,Hansoft/meteor,mjmasn/meteor,mjmasn/meteor,mjmasn/meteor,Hansoft/meteor,mjmasn/meteor,Hansoft/meteor,Hansoft/meteor