Fix collision with 'hashchange' event handlers

[john555]

Fixes issues:
#24

• Adds ability to update location.hash without page reload (using the history API)
• Adds the ability to dispatch a hashchange event to be handled by listeners.

Related issues:
#5
#12

[Bjornjansfelt]

Hi @mauricevancooten thank you for a great component! The only thing I'm missing to make it work along with some scrollspy package I'am relying is this pull request. Is there a plan to merge it? :)