404 and 500 stub pages.
Renamed constants
Refactored constants and use 404 page redirect

Use 404 page for invalid requests.
Add hover tooltips on map; Fix FB URL.
Added App Id
Updated view html

Add names for destination names so they could be shown on the map.
Arranged header social buttons.
Renamed trip view url.
ignore settings.py
Allow all hosts, for testing only.