methods isInvalidIndex, isBoundaryIndex, extractBoundaryIndex

fix of operator- for traited classes

To achieve the maximal efficiency of traits approach is necessary to
change name type from std::string to const char*.
Moreover, I had to make the default trait public in another way. There
is a function creating and returning the generated Trait. At first sight
is seemed to me as bad idea, but the compiler can not work so
efficiently with it. Thus, it is better to have static function which
generates the object of traits.

Refactor

CSVDBG first test. Now i can represent only simple wariables.

documentation.