remove (non-const) char[N] overloads introduced because of string literals
remove (non-const) char[N] overloads introduced because of string literals

Cleaned up SFINAE helper classes and added even more comments.

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core