replace deprecated ifloor(x) with floor(Int, x)

[jpfairbanks]

ifloor is deprecated in 0.4. does this need to be wrapped in a version check to support both 0.3 and 0.4?

[johnmyleswhite]

Yeah, we can't merge this unless you're prepared to drop 0.3 support.

Otherwise looks good!

[jpfairbanks]

is it better to make a compatible definition of ifloor when using the new version

if VERSION >= v"0.4"
    ifloor(x) = floor(Int, x)
end

and just keep using the old api? In this case it seems not to matter but in general is that a bad idea for the long run?