Completed creation of mess form factor that supports polarized calculations; refactor: remove spaces before public, protected, private

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

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

ISingleton, IFactory and IFunctionalTest base classes. TestFactory now use them. New arguments handling in main.