Support for %d, %i and %f

[nicolasff]

Hello,

These two commits add support for %d, %i, and %f in redis commands.

Nicolas

[pietern]

Thanks for the patches. I think the one for %d can be applied, with the reservation that it would be better to immediately include padding and the other features you would expect for a printf-style. I think the %f one should not have a fixed precision, this is not something users will expect. Maybe it's better to scan the characters until a valid full printf-style argument is found that is not handled by Hiredis itself and pass the entire thing to the native printf / sdscatprintf function. This would give us everything printf can do in one go. What do you think?

[pietern]

We've discussed this, but for historical reasons: full printf support is introduced in antirez/hiredis@7684d55