Changes in project structure

- Created directories for publications and researches sections.
- Created layout for pages with extensive content.
- Changed the project pages to PHP in order to automatically recognize
constants like de application root
- Restructured pages to re-use common HTML, such as CSS and JS imports,
navigation bar and footer.
- Insertion of JS code to auto recognize the current active tab on the
navbar.
- Re-alocated the network thumbnails to a single subdir.
- Removed Bootstrap dependency from JS directory and began using maxcdn
import.