Alexander Ziegler / gammalib

# Conflicts:
#	AUTHORS
#	include/GTools.hpp
#	src/support/GTools.cpp

# Conflicts:
#	ChangeLog
#	NEWS

The GFft class implements a one-dimensional Fast Fourier transformation. The GFftWavetable class is a support class for GFft and holds the trigonometric coefficients for a factorisation.

An initial implementation of the GNdarray class has been added that implements a n-dimensional double precision floating point array.

…d gammalib::rstrip_chars() function

The gammalib::str() floating point conversion functions now make sure that no precision is lost in a string conversion (well, roughly).

…ent() method since it was actually not needed, added check for unique name of model components, added function to find out if a string is contained in a list of strings to GTools

Time setting and getting methods for Julian Days, Modified Julian Days, native seconds and native days are now available that allow specifying the time system. Currently, TT, TAI and UTC are supported.

Methods have also been added that return the Greenwich mean and apparent siderial times, and the local mean and apparent siderial times that depend on the geographic longitude.

Finally, a now() method has been added that sets the time to the current time.

…mmalib into 1706-composite-models

…ients argument (#1847)

The eval_gradients() methods duplicate much of the code of the eval() methods. To increase the maintainability of the code, the eval_gradients() methods have been removed, and the computation of partial derivatives is now done by the eval() methods if the optional gradients argument is set to true.

If an application is constructed from the command line arguments with the --help option the application parameters are not loaded, and the destructor saved before the empty parameter container to disk, which effectively emptied the parameter file. Now the desctructor only save the parameters if they have been loaded before.