enable varargs in Query-facade and Traversable

Not sure if this is a good idea…

Tests are sparse considering the changes on the method signatures in the fundamental facade without integration testing the clients (local backend).

with the changes the following cases are covered:
- (1) from( element ) --> [element]
- (1) from( element1, element2, … ) --> [element1, element2, …]
- (2) from( array_of_elements[] ) --> [element1, element2, …]
- (3) from( iterable ) --> [element1, element2, …]
- (1) from( iterable1, iterable2, ... ) --> [iterable1, iterable2, …]
- (2) from( array_of_iterables[] ) --> [iterable1, iterable2, …]

1) params are varargs
2) params is array treated as varargs
3) param is iterable (precedence over varargs method signature (1) ) - is this even intuitive ??!