Flight aggregation now done at end of flow.

If flow is too short for FFT, use IATs directly.
Max and min for RTT estimate are now function arguments with defaults.
tcpflight.py now has single process mode for debugging.
Changed microflight update rules.

Previous IAT is now only updated when progressing in current uflight. On
restart, no update is performed. This allows recurring gaps to be
detected correctly. For example:

[ 5, 1000, 2000 ]

If 1000 triggers a new microflight, 5 would serve as the reference for
the next IAT. Otherwise we would need IAT to increase by g_thresh to
behave correctly.

An exception to this behaviour is when g_thresh is not surpassed, but
transport layer issues force a new uflight, as is the case of a loss.
In this case, prv_iat should be updated as normal.
Tune _prv_iat on buffering. No predetermined maximum for transmission
time now.
Removed MSS discrepancies being grounds for uflight segmentation.
Causes bad interactions with aggregation of flights later in the case of
packet pairs where the second packet is < MSS.

Example added to /data/
Initial microflights were not being timebinned appropriately.
Fixed _prv_max which was being incorrectly set to 0.
Fix to debug print so as to generate correct input for tcpflight (print
as int rather than bool / None)
Updated data files to include flows for which no grtt available.
Changes to how _prv_iat and _prv_max are calculated during buffering
phase.
Do not use RTT estimates which result in excessive gaps.
GRTT is no longer weighted average
Code cleanup mostly.
Reducing analysis to first N flights per flow.
Cleaning up unnecessary variables.
Export cleaned up.