Rename `EventLoopFuture.mapFromRESP` to follow 'map' semantics
From #48 (closed):
EventLoopFuture.mapFromRESPis not a
map-like function for 2 reasons:
- because it may fail, ie. go from the future's success track to the future's failed track and that's not something map functions usually do.
- it doesn't actually take a function to
map. Maybe should it be named