no need for "AlgorithmType" in each variable name, as all these variables sit in namespace AlgorithmTypes

new file Fit/FitKernel/AlgorithmNames.h so that Fit no longer depends on Core/Basics/BornAgainNamespace.h

Basics mainly contains base classes; Tools contains utilities that are definitely not meant for inheritance

Merge branch 'sampletree' into develop: This resolves #1527, simplify containsMagneticMaterial, printSampleTree, genPyScript.

all labels are now set through template function ISample::containedSubclass<>() instead of visitor mechanism

in typedef materials_t: LabelMap<const IMaterial*> -> typedef std::map<const IMaterial*, std::string>

ISample::containsMagneticMaterial() now without use ISample::containedMaterials(), to decouple concerns and prepare for change of the latter

pEqual(const IMaterial*, const IMaterial*) in IMaterial.cpp now fully replaces definesSameMaterial(..)

insertMaterials moved from visit() to top-level; for the moment, called on all IMaterial* pointers, including duplicates.

No harm for previous usein ISample::containsMagneticMaterial(),
and prepares for use in Python code dump.

prepare for refactoring Python export; simplify OrderedMap -> LabelMap, and move it to where it is used

regenerated bindings; rm SamplePrintVisitor.*, which is fully replaced by to_str() in ISample and derived classes.
This resolves the second third of #1527