Fix & Update Change Log; add 2.1.4 info where necessary.

Updates here include:

- Fixing nested list formatting in the change log (nested lists need line breaks and proper alignment, [reference](http://docutils.sourceforge.net/docs/ref/rst/restructuredtext.html#bullet-lists))
- Adding change log, update guide, and download links for 2.1.4
- Small change to the Github Tags/Releases link on the Downloads page. Figured we might as well point to one working place right now. :-p