more work on class and method comments

Removed instance() from python functional tests; ISingleton and MaterialManager are (probably) thread safe now

Outcomment Python compilation.
Work on layout while studying code.

to replace Coordinate3D<int>

Removed duplicate function names (rho, r) from BasicVector3D.

Insert new header comment block, remove old one, manually improve file comments (defines / implements), change brief function description to doxygen format, remove some outcommented code

Lattice2DIFParameter now is a class, InterferenceFunction2DLattice is protected against zero denominator, fix in project file to correctly treat FP exceptions under mac/linux

Fixed bug in IsGISAXS Morphology file simulation (bug introduced during creation of a StrategyBuilder class) + some cleanup

Performed last corrections and tracked down IsGISAXS bugs (see TestIsGISAXS7.h for more info in comments)