Translation Enablement & consider "seconds" translation

... multiple tr() added for Intervals. Compare Pane
... in Compare Pane - in time metrics check for both "seconds" and
translated tr(seconds) (following the concept for time as at most other
places where units == "seconds" are checked

(cherry picked from commit 6c78b00b65a1d794eb99038f21d6e705d119d29e)
Translation for Filter/Autofilter

... Filter/Autofilter did not consider Translation of the Filter
Criteria - using Special Fields (to translate from internal to external
names is working for me - but do special fields cover all variants?)

(cherry picked from commit 5cc4218a2a0877a1f8ff4f36d1367bee37c34d2d)
Calendar Chart now honours colour preferences

.. think that is the last of all the charts now done.
No smoothing applied when smooth < recIntSecs

.. its pointless

.. it is a big performance overhead

Fixes #753.
Turn smoothing OFF if smooth < recIntSecs

.. i.e. don't do ANY smoothing

.. last commit fixed performance but really adds
   no value to smooth data to the interval it was
   recorded at !!
Don't allow 0 smoothing in compare mode

.. we need all intervals to have a common smoothing
   applied or it breaks the charts
Merge pull request #903 from Joern-R/pull1

Translation Enablement & consider "seconds" translation
Fix time tooltip on AllPlot
Fix useMetric in Scatter plot

.. was broken when we moved useMetricUnits to the
   Athlete class and a local bool remained.
Fix color or red wavy line text

.. in the ride editor
Fix new CP chart show bests

.. didn't show bests and model till date range changed
   in settings or GC was restarted.
Darker flat chrome Linux/Win

.. makes for a better match to the chartbar and sidebar
   items when in flat mode and not on a Mac.
Fix Overlay Widget colors

.. and along the way discuovered context is not initialised
   correctly in GcChartWindow !
Translation Enablement & "seconds"

... more tr() changes
... added comparison for  both "seconds" OR tr("seconds") to all other
occurences found
... added "Lap" text for Intervalls imported in Garmin FIT format (this
is what Garmin delivers)

(cherry picked from commit ad790f05a386e3ae5c5b9dc129a216ac451b8cfc)
Fix Date Range Drag and Drop

.. internal move
.. that was hard!
Merge pull request #905 from Joern-R/pull1

Translation Enablement & "seconds"
Compare Pane Table better color support

.. headings color and remove frame
Support Metric Names with "special characters" for Column Chooser Drag&Drop

!!! please check if this right way to do it.
... column names containing special characters (here greek "average"
sign) did not work in Drag&Drop (even though they should be part of
Latin-1 (after changing in Mime to UTF-8) not only the greek characters,
but also "TM" works without special treatment)
!!! is this valid for all platforms ?!!!

(cherry picked from commit b4d1a7d3041beec686c7262cfa65bac8cf6e2179)
Merge pull request #906 from Joern-R/pull1

Support Metric Names with "special characters" for Column Chooser Drag&D...
Move wpk array next to watts array in cache

.. so we can read them both in with a single
   read -- this is to support an update where
   pd estimates support wpk and absolute watts.