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"
Merge remote-tracking branch 'upstream/master'