Optimise images
Update index.html:
* Update links
* Some links should be opened in a new window/tab
* Add small-text below photos in tab-panel
* Update #tab2 (Voluntarios y amigos) in tab-panel
Update colabora.html texts and make external links to be opened in a new window/tab
Update huancavelica_datos.html:
* Remove line from sidenav
* Images can now be clicked (still need to find out how to zoom over them)
* Fuentes shouldn't stand out so much
Move photos button in programa_local to a more visible place
que_es.html: add button that will lead to "Reseñas"
Update tiny details in programa_internacional.html
quienes_somos.html: links to external websites should always be opened in a new window/tab
Fix typos and update voluntarios.html
New page: quinuales.html