Removed a TODO item.

Didn't add any code, as the solution for syncing the live demo is a script that
runs locally on my development machine.  As it contains info about the host
server, I've decided to keep that out of the public repo.
Shorten button ids and attached functionality from inside <script> tag.

This is in the way of cleanup.  Changed button ids from, e.g. 'button-punch' to
'punch'.  I mean, we already know it's a button -- that's its element type.

Moving the functionality involved attaching the click function from inside the
page's <script> tag, instead of using the 'onclick' attribute of the element.
This seems like a better division of code, keeping markup and behavior
separate.
Clicking anywhere punches the clock by default.

Stop propagation on the 'clear' button to get this to work, as well.

Leave the 'punch' button on the page, even though it has nothing specifically
bound to it.  This gives users a clue about how to punch the clock, if they
need it.
Clicking anywhere punches the clock.