* Breaking change: Change `Teds\Vector::__construct` to add an additional parameter `bool $preserveKeys = true`,
and use the original keys of arrays/Traversables by default, throwing for non-integers and invalid integer offsets.
(Similar to the behavior of SplFixedArray::fromArray)
* Convert references to non-references when creating values from iterables.
* Minor performance improvements of `Teds\Vector`