added variables.scss

a comprehensive list of all the default variables so that you can easily override them on each project.
Added basic margin for form elements that missed it.
Added basic margin for form elements that missed it.
Moved the padding to the anchor tag.

This allows the entire list element to be clickable, and gets rid of the issue of clicking on an li and having it close the dropdown but not activate the link.
Fixed block-grid clearing
button-fix

html include button and .button for buttons and button groups
nesting section fix

this fixes a problem where a <section> inside a [data-section] would cause problems
update breadcrumbs

with this update you can also use the breadcrumb layout:
    <nav class="breadcrumbs">
      <a href="#">Parent</a>
      <a href="#">Child 1</a>
      <a href="#">Child 2</a>
    </nav>

with the negligible differences of $crumb-slash being slightly smaller due to inheriting the $crumb-font-size and losing the $crumb-link-decor because it would also apply to the $crumb-slash.
Changed default-opposite variable to opposite-direction
RTLified all the SCSS things
Merge branch 'master' of github.com:zurb/foundation into f4-rtl
Checking JS RTL support
Merge branch 'master' of github.com:zurb/foundation into f4-rtl
Merge branch 'master' of github.com:zurb/foundation into f4-rtl
pulled from master
Simple typo fix

"...you have access to a grid mixins..." -> "...you have access to grid mixins..."
Fix for font size setting on custom dropdown

The custom dropdown should be using the available variable $custom-dropdown-font-size.
Otherwise the size is fixed which causes problems in the grid if you change the fontsize of the standard inputs
Fix front-page typo

"site our app" => "site or app"

Probably a good idea to fix these little issues throughout.
Fix postfix/prefix vs. button-groups war, see #1677 and f24c3077049afc4522401cd38218215d4bdc50e7
fix for block-grid clearing problem