entry: log with spaces between all operands on *ln #25

[sirupsen]

Fixes #25

If this looks good to you @aarondl, I'll merge it :)

[aarondl]

In the sprintlnn function there's an extra Sprintln for no reason. We can simply return msg[:len(msg)-1] otherwise we're impacting performance.

Also this is another issue but I wonder if the savings of loc via code reuse is worth the performance penalty. What I mean is each Xln variant calls it's non-ln variant in an effort to reduce code duplication, but then we get two if statements and two fmt function calls. Just food for thought. This pull request absolutely fixes the issue, now I'm just prematurely optimizing haha.

[sirupsen]

Oops, good catch. :) Will definitely fix.

I prefer simplicity and consistency over marginal performance gains, unless we can prove it's actually hurting substantially. I've yet to have issues, or hear of, issues with the performance of logrus.