Add panel content only when tab is selected, call onSelect after selecting a tab if configured
Make tablist-top styles default, keep tabs on one line with horizontal scrolling, changed selected tab and panel classnames
Added methods to tabbify existing markup, removed unused styles from example
Deprecated ImageList
Added option to defer tab select (and content load) for first tab added
Adding sinon dev-dependency
Added tests
Merge pull request #5 from jmfee-usgs/WEBARCH-59

merged.