Allow a configurable selector for slides
Move typography variables towards the top.

It's very useful to be able to reference typography variables as values
to other components. For example,
`$price-title-font-family: $header-font-family;` is only possible if we
move typography variables above the other component sections.
fix support link on docs
Merge pull request #4132 from jaredcobb/organize-variables

Move typography variables towards the top.
remove open sans from _settings.scss, closes #4167
Merge branch 'master' of github.com:zurb/foundation

Conflicts:
	scss/foundation/_settings.scss
also remove -open-sans variable, closes #4167
Merge pull request #4079 from sdhull/orbit_slide_selector

Orbit: Allow a configurable selector for slides
Merge branch 'master' of https://github.com/zurb/foundation