Add example for downloading coincidences
Rename api.Network().stations_numbers

to api.Network().station_numbers
To improve name consistency.
Properly skip stations in HiSPARCStations

When station info cant be found and allow_missing is True,
really skip those stations.
Improve downloading more coincidences later on

Now possible to download multiple times to same file.
Event and coincidence ids properly increment.
Add longer timeout to download_coincidences

Make timeout 15 instead of 5 minutes.
This allows more dates to be checked for coincidences before timing out.
Add local station info data

Similar to the hard coded values for Science Park stations.
The JSON makes some offline work possible.