changes to "Speakers" section

[aristiles]

Key Speakers Call for speakers opening soon

Maybe we could change this to reflect more of a timeline, since we get so many questions about that? So we could break out the calendar and decide:

• opening date for submissions (announcement of keynotes/featured/workshop speakers, too?)

• closing date for submissions

• opening date for voting

• closing date for voting

• tentative schedule announced

• schedule finalized (full price from this point on)

[teleject]

Need to come up with a timeline :)