Make Timestamps Relative plugin

The Make Timestamps Relative plugin can be used to modify timestamps in the log such that all traces start and/or end at the same time.
- If you only select a start time, all traces will start at that time. The timestamp of the first event of the trace is set to the given time and all consecutive events get a timestamp that is equally sooner or later (absolute time difference between events is preserved)
- If you only select an end time, all traces will end at that time. The timestamp of the last event of the trace is set to the given time and all previous events get a timestamp that is equally sooner or later (absolute time difference between events is preserved)
- If you select both start time and end time, all traces are stretched to start and end at the given times. The timestamps of first and last event are set to the given start and end time and all intermediate events get a timestamp that preserves the relative time difference between the other events

