*: cleanup TODO

TODO

@@ -37,11 +37,8 @@ TODO:
 * organizer support to groups
 * meta range: move id to meta objects and return plain types (?), then remove id from meta base and meta ctor too
 * refine the storage fallback mechanism for views (ie alloc?)
-* sigh_mixin: automatic signal registration
-* sigh_mixin: change cb signature from reg/entt to storage/entt (breaking for the good)
 * don't pass reactive storage by default to callback
 * runtime types support for meta for types that aren't backed by C++ types
 * dtor, traits and custom should be part of meta descriptor maybe (?)
 * allow attaching const values of non-Type type to meta types
 * built-in no-pagination storage - no_pagination page size as limits::max
-* avoid specializations of sigh_type in basic_sigh_mixin due to alloc type