Reveal - consolidation of verbose animation options

Consolidated a bit of code (duplicated `setTimout` blocks)

My intent was not to change the effect of the code, but the first commit addresses issue #2767:
If no animation options are set, the `show` method returns [here at line 301](https://github.com/zurb/foundation/blob/master/js/foundation/foundation.reveal.js#L301), but it never gets the calculated top offset from fade or fade&pop. This reduces code and allows `animation:none` to get the proper offset.

The other two commits are purely consolidation.