Clicking on anchors in the header should work instead of toggling the me...

Clicking on anchors in the header should work instead of toggling the menu

Status: **Ready to merge**

Reviewers: @scalvert 

## Changes
- moved the preventDefault into the condition check so we only toggle if we match
- exit the event handler if we're clicking on or inside an anchor

## How to test-drive this PR
- checkout this branch
- `grunt test`
- `grunt serve`, ensure no linting errors, and check the examples - specifically test the default example, and bellows within bellows