Michael Mayer / gammalib

…mmalib into 1706-composite-models

…mmalib into 1706-composite-models

…mmalib into 1706-composite-models

…mmalib into 1706-composite-models

…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.