Accents modified in the DataAltiExtrapolation_Valery() documentation, to avoid warnings during the compilation of the manual

To be perfectly in CemaNeige functions examples, "BasinInfo$HypsoData [51]" is replaced by "median(BasinInfo$HypsoData)"

The CreateInputsModel() and DataAltiExtrapolation_Valery() function allows both POSIX formats (POSIXct and POSIXlt). #3896

#3896 The function SeriesAggreg() accepts input dates in both POSIX formats (POSIXct and POSIXlt). The output is in POSIXct format.

Adding an example for the "FixedParam" argument in the documentation of the CreateCalibOptions() function

Signed-off-by: Olivier Delaigue <olivier.delaigue@irstea.fr>

Signed-off-by: Olivier Delaigue <olivier.delaigue@irstea.fr>