Domenico Tiziani / gammalib

Removed all the deprecated code fragments from previous MC generation method.

'update_mc_cache()' now initializes an object of type 'GModelSpectralBrokenPlaw' used in MC generation.
Removed the entire batch of code which generates from a broken power law and replaced with generation of energies from the GModelSpectralBrokenPlaw::mc() method.

# Conflicts:
#	ChangeLog
#	NEWS

Added gradient formulae.
Added helpful notes.

Previously neglecting the appropriate handling in the CDF computation of the different indices above and below the break energy.
Now appropriately handles the case where (Emax < Ebreak) and (Emin > Ebreak).

Both methods for specifying the parameters of a "SmoothBrokenPowerLaw" model in an XML file are now supported.
Updated the test to reflect the actual way a spectral model is constructed in GammaLib.
The method still has some issues when generating the monte carlo. This is being worked on.

Implemented special handling in the MC event generation for when either (or both) the indices are -1.
Removed unnecessary vectors used for MC event generation.

Implemented Monte Carlo code for generating events from broken power law distribution, then rejecting based on relative values of the power law vs smoothly broken power law.
Still need to implement special handling for when one of the indices =-1.

Implemented 'read()' and 'write()' methods.

Added methods for numerically computing the flux.

Added "GModelSpectralSmoothBrokenPlaw.hpp" to "GammaLib.hpp"

GModelSpectralSmoothBrokenPlaw.hpp:
- Added the 'pivot' parameter and relevant methods.
- Added cache parameters for various values to aid in the computation of parameter gradients.

GModelSpectralSmoothBrokenPlaw.cpp:
- Added 'pivot energy' to model definitions.
- Updated documentation text.
- Updated '::eval()' method and gradient computations (still need to add gradient formulae for 'pivot', 'breakenergy', and 'beta', next commit)

Added methods for setting/getting the 'beta' parameter.
Updated the documentation text for several methods in the '.cpp' file
Still many methods to be updated before testing can be done.

Added ".cpp" and ".hpp" files for new GModelSpectralSmoothBrokenPlaw spectral model class.
Method still not fully implemented.
Still need to add ".i" files.

… of GModelSpectralNodes and GModelSpectralFunc

The GModelTemporalFunc implements a temporal file function for the simulation of transient sources.

The GModelSpatial::region() method returns a pointer to a sky region that fully encloses the spatial model component.

Changed method name component_scale() to scale(). Changed member names from m_component_names to m_names and m_component_scales to m_scales.