reader conditional extension for editor/build targets

[selfsame]

extend arcadia's reader conditional clauses to include :editor and the build targets (https://github.com/arcadia-unity/Arcadia/blob/develop/Helpers/UnityStatusHelper.cs)

[timsgardner]

@nasser what's the what on this?

[nasser]

There's a possibility of using Clojure 1.8's reader conditionals to exclude code from export via

#?(:arcadia/editor (editor only expression))

[timsgardner]

One (possibly paranoid) worry is that this might break something on the tooling side, or down the line on the compiler level for ClojureJVM/ClojureScript. I remember hearing the reader dispatch system is intentionally not open, so we should make sure adding stuff to it doesn't screw up some important part of the existing ecosystem in a weird way.