First draft of dropdown file downloads.
Top Nav Style & Content Changes

* PDF link now includes a drop-down for other formats (WIP).
* Change text based on width of screen to avoid wrapping.
Style for PDF drop-down nav.
Footer alt file buttons.

* Made PDF button bigger than other format buttons.
* Placed Dropbox button on end.
* Added DOCX format button.
* Added TXT format button.
Merge pull request #9 from TheSeg/alt-file-downloads

Alternative File Downloads