Cogs.Collections 1.12.1

This library provides a number of utilities surrounding collections:

• EquatableList<T> is an immutable list of items which may be compared with other instances of the same type and produces a hash code based on the permutation of its contents.
• NullableKeyDictionary<TKey, TValue> and NullableKeySortedDictionary<TKey, TValue> are very slim implementations of IDictionary<TKey, TValue> that allow a single null key (useful for some edge cases in which a null key is simply going to happen and you need to be able to deal with it; otherwise, use other dictionary classes)
• ObservableDictionary<TKey, TValue> and ObservableSortedDictionary<TKey, TValue> are counterparts to the BCL's Dictionary<TKey, TValue> and SortedDictionary<TKey, TValue>, respectively, that implement the also included IRangeDictionary<TKey, TValue> and INotifyDictionaryChanged<TKey, TValue>. Ever want to add multiple items to a dictionary at once... or keep an eye on what's being done to it? Now you can.
• OrderedHashSet<T> is a counterpart to the BCL's HashSet<T> that maintains the order of the elements in the set. All operations are still O(1), just like the original, but if you enumerate over it you will get elements in the exact order they were added. There are also methods for manipulating the order.