scope=block of "Eval in REPL" is misleading

When I first saw "Block" in "Eval in REPL", I thought it would evaluate a `defn` which the cursor is in.

For example, this Clojure code is in a buffer:

```clojure
(defn add [i j]
  (+ i j))
```

The cursor is on `i` or `j`, then "Eval in REPL" with scope=block sends only `(+ i j)`, not the whole `defn` code.

If this is an expected behavior, "Block" is misleading. "Expression" is appropriate for it.

And, I desires the real "Block" feature.

FYI: Seemingly, it supports only Clojure, but, obviously, it also works with other Lisp-family languages. I tried it with Common Lisp, and it worked in the same way as Clojure.

https://github.com/wuub/SublimeREPL/blob/master/text_transfer.py#L178