No location events

It happens quite often that events are scheduled while no location has been found yet. See #102 

This is a raw draft to support this in the platform.

Some things that need to be done:

* [ ] finalize the texts
* [ ] translate to en
* [ ] allow some sharing options a la "hey we need a location dudes"
* [ ] tests when functionality is settled

/cc @rubiii @erotte @alto @PragTob