Start extracting true_tstamp from querystring

[alexanderdean]

Quick points:

• true_timestamp is for when the instrumentor knows the real timestamp for the events being sent
• true_timestamp != device_created timestamp
• There should be a flag in a given tracker to specify whether a user-specified timestamp should be the true timestamp or device-created
• If true_timestamp is set, this should be used for the derived timestamp

[fblundun]

Would this be a new field in atomic.events, or would the true timestamp just go directly into the derived_tstamp field?

[alexanderdean]

I think it would be a new field and fed into derived_tstamp

[alexanderdean]

Note on this:

There should be a flag in a given tracker to specify whether a user-specified timestamp should be the true timestamp or device-created

When a tracker has an event builder pattern, we can make the specification of true timestamp versus device-created on a per track() basis, which will be more elegant.