CommandLine: add parameter "-datapath"

This Patch allows to specifiy the used DataPath for the XCS Data when
starting XCS with command line.
This will allow the direct use of the storage card in the Altair by XCS
(getting rid of the all omipresent storage problem in Altair), when the
AltairSync program will be updated by Triadis (otherwise the call is
still the same).
RoughTime: add operator+(RoughTimeDelta)
DataField/RoughTime: render values in local time zone

Implements TRAC ticket #2645.
LocalTime: move to src/Time/
AirspaceParser: use OperationEnvironment::SetErrorMessage()

Don't use MessageBoxX, remove UI dependency.
InfoBoxes/Factory: use static_enum to verify array size
po: update Japanese translation
TeamCode*: move to src/TeamCode/
ContestDijkstra: split Dijkstra specific code and trace management code

Create new class TraceManager which manages the trace point vector.
To be used later.
WindZigZag: delete obsolete class

This library has been replaced by WindEKF a few years ago.  We kept
the old version to be able to compare the two, but it is very obvious
that WindEKF is superior.  Let's delete it, finally.
Wind: move to src/Computer/
Merge branch 'master' of git://git.xcsoar.org/xcsoar/master/xcsoar