Ordered lists and tables in course overview and timeline are not styled well

[ragesoss]

In the styling for ordered lists, we don't show any numbers, even though markdown usually supports numbered lists in a simple way. Users have been trying to add ordered lists to their timelines.

[ragesoss]

Also, markdown tables completely break the layout.

[ragesoss]

@rileywho This is a high-value improvement that we could make pretty easily, once the design part if it is in hand.

[ragesoss]

Here's an example of a page that uses some of these features:

http://dashboard.wikiedu.org/courses/Stony_Brook_University/Health_Communication_%28autumn_2015%29/timeline

[ragesoss]

(A basic style for an HTML table will also be useful, but that could be a second-wave addition.)

[bmathews]

Looks like we can improve a lot of the base styles:

current:

---

traditional markdown formatting:

[bmathews]