#70 array::sort

[SGrottel]

We marked array::sort deprecated in favor of std::sort.

Two issues:

1. We already (almost nicely) can use std::sort: (tested with int-array)
   std::sort(const_cast<int*>(arr.data()), const_cast<int*>(arr.data()) + arr.size());

2. This construct is not thread-safe! The array should be locked during the whole sorting operation, which is not possible that way.

Thus I recommend we de-deprecate array::sort but replace it's implementation with the STL algorithm (but also using the collection's lock).

[SGrottel]

I changed (syntax, semantics, and implementation) of array::sort and fast_forward_list::sort accordingly, to be fully compatible with std::sort. I also de-deprecated array, as suggested.

One more idea:

1. We could implement array::begin(), array::cbegin(), array::end(), and array::cend() by simply returning points to the array elements, as suggested above. These pointer are equivalent to random access iterators. It is not type-safe at all, but it would work.

Opinions?