Fix possible division by zero.
Fix possible division by zero.

When 'maxCount' and 'minCount' are equal then 'relative' will return NaN.
Which result in font-size 0 on all tags in the tag cloud.

freizl/freizl.github.com-old,oldmanmike/hakyll,d12frosted/hakyll,freizl/freizl.github.com-old,beni55/hakyll,Minoru/hakyll,freizl/freizl.github.com-old,freizl/freizl.github.com-old,freizl/freizl.github.com-old,freizl/freizl.github.com-old,freizl/freizl.github.com-old,Javran/hakyll