Section selectors

Solution for #4513

If he does not want to add a section, then add a .section class instead. This was already done in part of the code. I only made the same change in the rest of the plugin.
Changed the section class to top-bar-section

As for #4513, this shoudl close it out. the .top-bar-section is defintely required to be there. However, now it could be a div if you really wanted it to be.
Fixed jumpy sticky Top Bar

Top Bar would jump to the fixed position too soon in situtations where Top Bar calculated the offset before all of the content above it loaded on the page.
Switched to self.S

Adhereing to the Foundation best practice
Trigger resize on load instead

This method is a little better in that it instead calls the window resize event.
Merge pull request #5582 from joeworkman/topbar-fixes

Topbar fixes