v0.6.0 - Orphan steps, namespaced events, small fixes

New:

• introduced support for orphan steps, through orphan option #109
• implemented vertical centering of the popover while scrolling the page #132
• added namespace to Bootstrap Tour events #124
• better integration with Twitter Bootstrap final 3.0.0 release

Fixed:

• if orphan is false, skipping a step now brings you to the correct step, based on the navigation direction