Thierry Louge / gammalib

It seems better to not introduce the alias method but to use a type constructor instead. This allows writing out the same model type that was read in, enhancing the compatibility with the legacy XML format.

The following new names have been introduced for the spatial model components:
* "PointSource" (alias: "SkyDirFunction")
* "RadialDisk" (alias: "DiskFunction")
* "RadialGaussian" (alias: "GaussFunction")
* "RadialShell" (alias: "ShellFunction")
* "EllipticalDisk"
* "EllipticalGaussian" (alias: "EllipticalGauss")
* "DiffuseIsotropic" (alias: "ConstantValue")
* "DiffuseMap" (alias: "SpatialMap")
* "DiffuseMapCube" (alias: "MapCubeFunction")

…for the case that the input map is not normalized (fixes #1584).

…lization in set_mc_cone() method as the fraction of the flux that is comprised within the simulation cone (#1558).

…ialDiffuseMap::set_mc_cone() method.

…for Monte Carlo simulations.

Remove the Monte Carlo cash computation from GModelSpatialDiffuseMap::prepare_map() method.

Rename GModelSpatialDiffuseMap::norm() method to  GModelSpatialDiffuseMap::mc_norm() and call GModelSpatialDiffuseMap::set_mc_cone() in that method.

Conflicts:
	inst/cta/include/GCTAObservation.hpp
	inst/cta/src/GCTAObservation.cpp

The norm() method has been added to the abstract GModelSpatial interface that returns the model normalization within a circular region. This is used in the GModelSky::mc method to correctly reflect the normalization specified in the XML file. The method is also used to flag sources outside the simulation cone (applies so for the point sources, radial source and elliptical sources).

The normalize attribute provides control over whether a map should be normalize or not. By default a map will be normalize to that the spectral model provides the correct fluxes, but for some specific analyses, normalization can now be switched off by adding normalize="0" in the XML file. The attribute has also be added as optional argument to the constructors. A unit test has been added that checks the functionnality.

Conflicts:
	inst/cta/Makefile.am
	inst/cta/include/GCTALib.hpp
	inst/cta/pyext/cta.i

Some of the newly introduced methods have been renamed to fit more the GammaLib standards. The GCTAEdispRMF class needs quite some rework, but I merge it in right now to have a working reference of the code. Some initial code modifications have been done, more to come soon.

…Map::mc method to reduce code repetition - I just moved the code from here to GRan

The coding and design conventions (CDC) document was also updated.

All methods returning a solid angle are now named solidangle().

The GSkyPixel class now handles 1D and 2D sky indices. This made the distinctive 1D and 2D methods in GSkyProjection and the derived classes obsolete. Now, all projection classes take GSkyPixel as argument.

The GSkymap class now uses the universal GSkyPixel class. Methods have been renamed consistently. An integer index is now consistently called "sky map index" and the GSkyPixel object is named a "sky map pixel". Methods operating on indices contain now "inx", method operating on sky map pixels "pix".

Add GChatter argument to print() method.

The print() method now takes an argument of type GChatter to control the chattiness of the output in a homogenous manner.
Pass NORMAL chatter level in __str__ method.
Add chatter argument to print() methods.
Use GLog::chatter() method to control the chattiness of the log stream operator.
Add chatter() methods and provide member access through const references.
Add chatter() methods, provide member access through const references, and declare one liners as inline methods.

The chatter() methods control the new m_chatter attribute that is used to control the chattiness of the object's print() methods.
name() and version() methods return const references.
logFileOpen() method now sets the chattiness from the applications's chatter parameter, and name() and version() methods now return a const reference.

The eval() and eval_gradients() methods now take a GPhoton object as argument to allow the implementation of energy and time dependent source morphologies.

GEnergy and GTime objects have been added to the mc() method interface to support equally the implementation of energy and time dependent source morphologies.

So far, no class really implements energy and time dependent source morphologies, but now we have the infrastructure to do so.

The GModelPar interface has been revisited and the code has been adapted to satisfy the new interface.

All diffuse spatial models are now derived from GModelSpatialDiffuse and named GModelSpatialDiffuseXXX.