Adds hrefBase props to nav.

Adds ability to set hrefBase in props.nav to set default protocol and
hostname for all links everywhere.

Had to hack account a little bit to make it work there too because it
doesn't follow the consistent nav structure as news and marketplace.
Fix Account Links in DemoControls

Update all references to account links list to just account links.
Fix Url Parser

Url parser was looking for '/' to separate hostname from path and
failed to separate hostname from query string without slash. Added
'?' as a separator.

Added test cases to url and href utils as well.
Add Slash to Homes Href

Just to be explicit, in case we ever support relative href, adds
slash to homes href for the sake of being explicit.
Fix Text in Demo Page
Fix Local Href Bug

+ Merge the nav group hrefBase with the child hrefBase before
assigning it to the child hrefBase in NavGroup.
+ Update default props so that local overrides hrefBase correctly.
+ Update comments in default props.
+ Update DemoControls defaults to demonstrate hrefBase override works
correctly.
Github Feedback

+ Comment out `testMe` in `href` util.
+ Remove `console.log(...)` from `NavGroup` util.
Merge pull request #25 from deseretdigital-ui/nav_props

Adds hrefBase props to nav.
Bump version to v0.3.0

Updates version to v0.3.0 which includes the correct logout path,
hiding of a border when account links are empty, and support of hrefBase
for better multi-environment support.
Adds .ksl-header--hidden class

Adds fancy feature that hides header when scrolling down past a
certain point and shows it again upon scrolling up or when at top of
the page.

Inspired by http://medium.com.
Don't Change Hidden State if No Change

Need to check the previous and current scrollTop to make sure they
are different. Otherwise, hidden state should remain the same.