Open browse view to the working directory of the currently open bview.

[PJayB]

I feel like this speeds up navigation in most cases.

One potentially controversial change is that this now sets the default cwd of new bviews to the parent directory of the file being opened. I hope this doesn't have any bad side-effects!

[tomas]

I think I need to try this out before I give you a thumbs up. Great work though!