Remove unnecessarily if statement
Small variable name changes for clarity
Add stub for escape_for_latex and refactor

Because the body of process_webpage was in a try/except that caught all
exceptions, we weren't seeing that escape_for_latex was missing. To
avoid this in the future, we remove the try/except and added a simple
stub for escape_for_latex.

We've also refactored process_webpage to check that required HTML
elements exist before operating on them so that we don't run into weird
runtime errors if Yahoo provides malformed or different HTML than we
expect.
Unpack elements in headline_list

This way we can name each element instead of having to remember indexes.
Simplify newsdate formatting

We spent some time in the datetime module documentation and found some
different ways to handle newsdate handling.

I've become a total format string convert :).