Merge branch 'feature/add-integersequenceentry' into 'master'

Feature/add integersequenceentry

The traits class `IntegerSequenceEntry` computes the i-th entry
of an `std::integer_sequence`. The `integerSequenceEntry` helper
function does the same with function syntax.
    
 This allows to avoid the hight template instantiation depth
 of `std::make_tuple` when using the "natural" implementation

```cpp    
std::get<index>(std::make_tuple(t...));
```
    
The latter adds 15 instantiation levels per argument whereas
the still recursive implementation in this MR adds only one.

See merge request !170