shared_lock: move assign doesn't works with c++11

[viboes]

When move semantics is supported by the compiler the shared_lock move assign doesn't works because boost::move is missing

        shared_lock& operator=(shared_lock<Mutex> && other)
        {
            shared_lock temp(other);
            swap(temp);
            return *this;
        }

The temp must constructor must use boost::move

        shared_lock& operator=(shared_lock<Mutex> && other)
        {
            shared_lock temp(boost::move(other));
            swap(temp);
            return *this;
        }

The same applies to the other move assignments.

[viboes]

(In [77291]) Thread: Fix #6673 and partial fix for 6671, 6672, 6675 which need to add the documentation and test