Fixes #9915.
Uses intrusive is_convertible in MSVC compilers.
Removes some throw conditions in the documentation produced by the allocator copy constructor (as the standard requires no-throw guarantee for those).
Fixed #9916: "Allocator propagation incorrect in the assignment operator of most".
Fixed #9932: "Missing assignment operator from related static_vector".
Added missing details from issue #9915
Fixes #9931 ("flat_map::insert(ordered_unique_range_t...) fails with move_iterators")
Reverted a (premature) optimization that can lead to out of bound write.
* Fixed BOOST_CONTAINER_NOEXCEPT_IF(allocator_traits_type::propagate_on_container_move_assignment) missing ::value

* Optimized insert_equal(ordered_range_t,...) and insert_unique(ordered_unique_range_t, ...) for elements to be inserted in the end.

* Added range insertion overload (non-standard extension) to vector taking the number of elements to avoid reiterations with std::distance.
Merge branch 'develop'