PythonGlue: check plausibility of all times
Flight: add LoadIGC method
FlightTimes: check for plausibility
Flight: add Times method
test_XCSoarTools: output first and last fix of flight path
Flight: add Analyse method

PythonGlue's Analyse function declares a char** list which forces us
to compile with WERROR=n atm... :-(
skylines: add README