Make "Allow events outside observation period" = TRUE by default

[dimshitc]

I can't think of any use case when we need this field unchecked: For example, if I want to exclude patients who have differential diagnoses, the same observation period doesn't matter. Or a condition as specific complication of underlying condition (i.e. Psychosis in Dementia), it also doesn't matter if these two diagnoses were given in different observation periods. Or specific drugs after the index diagnosis to increase specificity - does it matter if they are given within the same observation period?

[p-hoffmann]

I agree enabling it seems to be the more common case. I've made it the default for now.