Mark all calls as safe for now
Mark all calls as safe for now

This is to avoid "stopping the Haskell world" until the call completes.
Calls that are guaranteed to return in a short period of time will be
changed back to "unsafe",  however cursory review of libpq source code
suggests that even calls that one might think "should obviously be marked
as unsafe" perform synchronous IO.

lpsmith/postgresql-libpq