added new test for iterator_dressing
 cosmetics for gf

little cosmetics for imtime
utility : add aux data to dress_iterator

- adding optional pointer to auxiliary data
typically container, which is useful in some
cases.
- added new example iterator_dressing3
tuple_tools : add apply for a simple function

- NB : does not work for a method, use a lambda in this case ...
array/h5 : fix compile bug with h5

- detection of array of strings was causing
compilation error for non array object.
- now : one function for array,
the difference between string and not is pushed
below in implementation.