Improve efficiency of patch

[radarroark]

Currently, when patch adds/replaces values in vectors, it creates two subvecs and concatenates them. Concatenation is O(n) for normal Clojure vectors so this is inefficient. This PR makes patch replace values in vectors with assoc, and add values in vectors with conj if the value is being added at the end of the vector.

I also replaced (set/difference x #{p}) with (disj x p). This may not affect performance but I figured it's more readable, and lets you remove dependence on the clojure.set ns.

[huahaiy]

LGTM. Thanks!

[radarroark]

Thanks @huahaiy. If you don't intend to cut a release soon, could you add a deps.edn file to the root of the repo so editscript can be pulled by clojure CLI as a git dep? Even just putting {:paths ["src"]} in the file would be enough to make it work.