The 'except' function doesn't work properly on dictionaries and sets

[BrucePay]

For example:

 (except {:a 1 :b 2 :c 3} {:a 1} | first | type-of)
^System.Collections.Generic.KeyValuePair`2[System.Object,System.Object]

should return a new dictionary with the {:a 1} pair removed instead of a list of pairs.

Likewise for sets:

=>  (except #{:a 1 :b 2} #{:a 1} | type-of)
^BraidLang.Vector

should return a new set with the members removed instead of a Vector of elements.

[BrucePay]

Make sure to update the docs in "helpsource.tl".