Editor - parsing crashes with more than one newlines

[monkey-w1n5t0n]

The first two evaluate fine, the third errors with malformed program:

(+ 1 2 3)

(+ 1 2
   3)

(+ 1 
   2
   3)

It seems that the parser receives the string truncated at the second newline, so it tries to parse (+ 1 2 and 3) separately.

[monkey-w1n5t0n]

Fixed here.