Adds timeline view scaling.

Squashed commit of the following:

commit 471b6d3ea64dfad8598f8ebde5f44ed47ed02d38
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Sun Aug 31 18:14:27 2014 -0500

    Removes dead function.

commit 0864dd143ce30b0225b493be446b3b1ce901cec2
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Sun Aug 31 18:09:58 2014 -0500

    Scales scrubber, properties and property tracks.

commit 72df12c87bea6747c0f4f5ba75b1465377a20669
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Sun Aug 31 16:46:08 2014 -0500

    Sets up time scale as a constant and gives it an IncrementerView.

commit a22ff1b901f853d6e37e8127d09a7834ec06b630
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Sat Aug 30 11:23:53 2014 -0500

    Lays out timeline scale DOM and styles.