OLCTriangle: include finish point into search interval

The allowed points inside the closed trace is a closed interval
formed by [from, to], whereas a candidate set expects a
right-open interval of [from, to + 1).
OLCTriangle: relax shortest leg check a bit

The former 8/29 == 27.58% was a little bit too strict for some
border cases - this caused the algorithm to miss a better triangle
only if the origin of the flat projection was moved by some meters.
The new check 11/40 == 27.5% fixes that for the examined flights.
po: update French translation
po: update Swedish translation
DebugReplay: move NLineReader out of DebugReader class

Prepare creating a DebugReplay from a std::vector.
IGCFix: Apply() copies extentions, too
DebugReplayVector: implement replay from memory

This class shall be used for replays directly from memory, for example
for replays from a database (like the live tracking data) or if someone
wants to reduce file-IO for some reason.
python: initial python module commit

This python module does nothing more than reading a IGC file and
storing it in memory if desired.
python: add FlightPath functionality...

... but without path reduction yet.
python: add small test script
build/python: add build instructions for xcsoar python library
python: add takeoff/release/landing detection method
DebugReplay: add detail level

Each fix should have a detail level at which it will be shown on
a map. This is only useful for skylines atm.
Flight: make flight reading code it's own method
IGCFixEnhanced: add clock
python: implement polyline reduction code
DouglasPeuckerMod: add hard limit for number of points
PythonGlue: fix start and endtime of polyline reduction
python: implement flight analysis
python: implement google polyline encoding