Refactor and add new algorithms.
Add the index_based_iterator.
Add facilities to perform O1 key lookup.
Add `boost::mpl11::always`.
Simplify `map<>` by using `vector<>` in its implementation.
Remove inline namespace v2 and comment namespace closings.
Remove several useless headers from the old mpl11.
Split the placeholders into several files.
Support non-metafunctions in `quote`.
Attempt to add concepts.
Move everything to the sandbox in order to create a stable trunk.
Re-add content from the sandbox, making sure everything works.
Add `category_of` and use function overloading for tag dispatching.
Don't pass the operation's tag when applying dispatch<>.
Add several views.
Add `vector`.
Add temptative concepts.
Add `detail::dispatch_category`.
Add comparison metafunctions.
Move views into views/.