Suggested I/O limits in openquake.cfg are too small for demos

[Daniele Viganò]

Some demos (i.e. ScenarioRisk) won't run with the suggested default numbers for the output weight limit:

# maximum size of the output in some units; 0 means no limit
# for a laptop, a good number is 2,000,000

ScenarioRisk produces an output of 2.237.000

We should check also

# maximum weight of the sources; 0 means no limit
# for a laptop, a good number is 200,000

[Michele Simionato (michele-simionato)]

We need to revisit the limits anyway. In the near future the GMFs will be exported in HDF5 format, so the size of the exported output will be completely different. It is fine to raise the limit right now to 4,000,000.

[Michele Simionato (michele-simionato)]

Also, at some moment in the future we will need to move the limits in oq-lite.