[fix bug 897140] Upgrade people templates to Foundation 4

This PR upgrades the people app to Foundation 4. Aside from the new mobile-first grid layout, key changes include:

* The people app is now fully keyboard accessible. All links, form inputs and click-able page elements now have focus styles and correct `tabindex` ordering. 
* Foundation dropdown form elements have been dropped in favor of native browser `<select>` inputs. Same goes for custom `checkbox` elements, as these we're not keyboard accessible and provided little value in terms of styling.
* `.pictogram` icon font syntax has been improved to use generated content instead of exposing random characters in the markup. This is a win for both semantics and accessibility. (I was going to make a separate bug/pr for this, but as I work through migrating pages I think making this switch now will actually be easier).
* The AJAX request on the main people page was busted in IE8, making the people app non-functional. I've fixed this by updating the syntax to use the jQuery `$.ajax` method. A quick win as the site now works for that browser.

It's also worth pointing out that I've had to put in a few conditional checks in `app.js` for method calls that are only relevant to Foundation 2. They no longer need to be called for pages that have been migrated to Foundation 4.

There is also some new conditional logic in `map_modal.js`, as the map data now needs to be loaded once the reveal modal is shown (due to changes in Foundation 4 CSS). For pages using Foundation 2 the map is still drawn on DOM ready.