Support child elements inside data-dropdown anchors

If data-dropdown anchor contains a child element (like an image for an
icon), this code will allow the appropriate dropdown functionality to
execute even when those child element are clicked.
Fix Split Button example markup.
Conflit between multiple section

Please find the following samples which show the problem:

Foundation 4.3.1: http://jsfiddle.net/JwbMG/2/
Foundation Master: http://jsfiddle.net/JwbMG/3/
Foundation Master (patch): http://jsfiddle.net/JwbMG/4/

When a user select a region of a section, the other section is reinitialized.

When an extern anchor is clicked all sections are reinitialized.
Fixed performance of forms refresh_custom_select
refresh_custom_select was looping twice thru the select options:
- once using $() to create the li elements
- then a second time trying to find the selected and disabled elements

this was causing the page to freeze when selects with many options were refreshed
instead the code was changed to construct the list's HTML with a string, and add
the selected and disabled classes at the same time if necessary.
fix abide sample
Fix "close" event for Reveal

Currently the "close" event is not being fired when the user clicks the
modal backdrop with closeOnBackgroundClick true, since the close event
is being triggered on the closest .reveal-modal parent of the target.
This naturally doesn't exist when the target is the backdrop.
Merge pull request #2941 from surrealist/fix-abide-sample

fix abide sample
Merge pull request #2944 from mhchen/reveal-background-close-callback

Fix "close" event for Reveal
Merge pull request #2895 from damirkotoric/dropdown-link-with-child-elements

Support child elements inside data-dropdown anchors
Merge pull request #2932 from raziel057/patch-2

Conflit between multiple section
Merge pull request #2934 from ziad-saab/forms-select-refresh-performance

Fixed performance of forms refresh_custom_select
Merge pull request #2926 from webflo/fix-splitbutton-example

Fix Split Button example markup.