Restructure UI

[acka47]

From #261 (comment):

• We remove the distinction between search vs. browse.
• On the home page, we have the search interface without the small map in the upper left corner. This enables quick loading of the result list with nearest institutions first shown.
• We enable switching between list and map views of the search result via tabs inside the homepage. (probably on the upper left of the result list) while facet and search bar stay untouched at their place.
• The map can load in the background and people can start looking/interacting with the result list. When they switch to the map they see a zoom with 5 km radius or so from their position.

Plus:

• We add an "About" page holdign the information currently on the home page.