Implemented order

Implementation of https://github.com/mikera/core.matrix/issues/84

Some examples:
```clojure
(order [:a :b :c :d] [0 2 2])
=> [:a :c :c]
```
```clojure
(order [[:a :b :c]
        [:e :f :g]] 1 [1 2])
=> [[:b :f] [:c :g]]
```