R1:ee1e04e56275

Increase Phriction subdocument limit from 50 to 250

Summary:
A few users have come into IRC asking about this: basically, we show "children + grandchildren" until you have more than 50, then we show only children. This creates a few issues:

- This view is surprisingly useful, and becomes less useful after it folds.
- The folding behavior and program motivation for folding isn't obvious.

In the long term, some finessier approach is probably better here (configuration, CMS stuff, etc), but for now…