Fixed zero-size allocation

   if( this->size == size && allocationPointer && ! referenceCounter )

      return;

   this->releaseData();

   // Allocating zero bytes is useless. Moreover, the allocators don't behave the same way:

   // "operator new" returns some non-zero address, the latter returns a null pointer.

   if( size > 0 ) {

      Algorithms::ArrayOperations< Device >::allocateMemory( this->allocationPointer, size );

      this->data = this->allocationPointer;

      this->size = size;

      TNL_ASSERT( this->allocationPointer,

                  std::cerr << "This should never happen - allocator did not throw on an error." << std::endl; );

   }

}

template< typename Element,

          typename Device,