Posthog

1. When local evaluation is enabled, we automatically add flag information to all events sent to PostHog, whenever possible. This makes it easier to use these events in experiments.

1. Numeric property handling for feature flags now does the expected: When passed in a number, we do a numeric comparison. When passed in a string, we do a string comparison. Previously, we always did a string comparison.
2. Add support for relative date operators for local evaluation.

1. Increase maximum event size and batch size

1. Returns the current flag property with $feature_flag_called events, to make it easier to use in experiments

1. Restore how feature flags work when the client library is disabled: All requests return `None` and no events are sent when the client is disabled.
2. Add a `feature_flag_definitions()` debug option, which returns currently loaded feature flag definitions. You can use this to more cleverly decide when to request local evaluation of feature flags.

Breaking change:

All events by default now send the `$geoip_disable` property to disable geoip lookup in app. This is because usually we don't
want to update person properties to take the server's location.

The same now happens for feature flag requests, where we discard the IP address of the server for matching on geoip properties like city, country, continent.

To restore previous behaviour, you can set the default to False like so:

python
posthog.disable_geoip = False

// and if using client instantiation:
posthog = Posthog('api_key', disable_geoip=False)