Removed setting the body to display:none

I think it is better to remove this feature as it can do more harm then good.
For example if you try to get the height of an element with jQuery('#mydiv').height() the method returns 0 because the body is not displayed yet. 

Also not showing the body when loading can give the user the false idea that the page isn't loading at all.
Merge pull request #1 from Themekraft/master

Update
Merge pull request #14 from KoenRijpstra/master

Removed setting the body to display:none