Incorrect compiler message parsing for ocaml >= 4.09

Nobody has claimed this yet.

I sent a change to the OCaml compiler to change the format of the error messages https://github.com/ocaml/ocaml/pull/8541. It means that messages printed by OCaml >= 4.09 won't be parsed properly by this LSP server.

The change affects the messages that are on multiple lines. The message now contains the first and last lines. Also the second part of the characters section is no longer a byte offset, it is the position on the last line.

Here is an exemple.

```
File "robustmatch.ml", lines 33-37, characters 6-23:
9 | ......match t1, t2, x with
10 | | AB, AB, A -> ()
11 | | MAB, _, A -> ()
12 | | _, AB, B -> ()
13 | | _, MAB, B -> ()
Warning 8: this pattern-matching is not exhaustive.
Here is an example of a case that is not matched:
(AB, MAB, A)
```

The code to change seems to be in `AsYouType.re`:

https://github.com/jaredly/reason-language-server/blob/8f15f5d54dc8a46aede8d8ec4a77e6f1cbda78fb/src/analyze/AsYouType.re#L64-L78

Tuareg has a list of compilation messages that can be used for reference: https://github.com/Chris00/tuareg/blob/master/compilation.txt

Start with src/analyze/AsYouType.re at lines 64-78 and compare its parsing with the OCaml >= 4.09 example in the issue. Use Tuareg's compilation message list as a reference; done means multiline messages include the first and last lines and interpret the second character position as the last-line position.

Written by the indexing model from the issue text.