Bug fix: UNIX time & leap seconds

Removed leap second adjustment from the convertion of GNSS time to UNIX
time.

Also, refactored some code, added some more output data for validation and
updated the help.
Tried to add more complex analsys, not finished

I've tried to create more complex plots, but lost some features in the
process.

Refactored some code.
Added support for multiple axes.
Fixed major ploting issues

Finally got plotting to work as desired.
I think there is still a bug in the historgram and I should add stats to
the histograms
Fixed bug in applying XPPSoffset

Earlier, I decieded to convert the TIC measurements to nanoseconds, but I
forgot to change the equation for calculating differences, which still
included the same conversion.  So, the offsets were not being applied.
Also, added standard deviation and mean to historgrams.
Added arbitrary shifting of offset data

Added a new option to allow arbitrary shift of the xPPSOffset data set
with respect to the TIC measurement data set.
Fixed title in Historgram Plot
Fixed attempt to apply offset without offset data

Logic error was causing offset database to be referenced even when no
offset data input files are provided.
Minor text spacing fix
Changed input parsing for new TIC data format
Fixed problem handeling gaps in xppsoffset data
Partial Revert Bug Fix: 70b113

Should not have second guessed myself.  It is necessary to subtract leap
seconds, otherwise converting to UNIX time shows GNSS=UTC which is
wrong.
Merge branch 'dev' into public
Added script to harvest temp log from Trav Box

Chris G. contributed a scrip to retrieve the temperature data logs from
the Traveler Box temperature sensors.
Added mkRINEX+CGGTTS.sh
Merge branch 'dev' into public