Change status of prop#225, prop#238 and prop#243

Prop225: Draft --> Rejected It has been superseeded by proposal 250.

Prop238: Draft --> Finished Implemented and been upstream since 0.2.6.3+ as the HiddenServiceStatistics option

Prop243: Open --> Closed Implemented and merged upstream. Although, we need to modify dir-spec.txt since now HSDir need Stable, Fast and minium of 96 hours uptime. That's a trivial change.

With enough ACK, I'll proceed with the cleanup.