All event handlers should return the event data first

[levithomason]

As we rewrite away from jQuery, #206, we are no longer bound to Semantic UI event callbacks. In keeping things React friendly, all components will be required to return the event data as the first argument.

Any other helpful data can be returned after this. This will be a breaking change to the current MenuItem component as it currently returns the menu item name.

this.props.onClick(name)

will become

this.props.onClick(e, name)

This is the only breaking change, there are several other non-breaking changes that need to be made however. Note, the common test that has been written for this has currently commented out the actual assertion. See, commonTests.js it('handles events transparently'... once merged.

This issue is a reminder to address the issues above and enable the assertion ^ for event data.