MLT Parser ========== Mlt_parser contains functions for parsing `*.mlt` files, which contain OCaml toplevel sessions -- i.e., a series of statements followed by their output (in the form of [expect tests](https://github.com/janestreet/toplevel_expect_test)). The first of these functions, `split_chunks`, was extracted out of [Toplevel_expect_test](https://github.com/janestreet/toplevel_expect_test), where it's used to divide the toplevel session into "chunks", where each chunk comprises a set of toplevel code phrases (statements separated by `;;`) and the expect test they precede. The second, `parse`, is used by a tool that converts `*.mlt` files into `*.org` files. That tool needs to be able to distinguish OCaml code phrases, expect tests, and blocks of org-mode markup (delimited by `[%%org]` annotations).