Hook the integration tests into rust's test framework.

Instead of using a hacked-together shell script, use rust's test framework to do the comparison.

src/lib.rs

@@ -0,0 +1,8 @@
+#![feature(round_char_boundary)]
+#![feature(exit_status_error)]
+mod parser;
+mod compare;
+pub use parser::*;
+pub use compare::emacs_parse_org_document;
+pub use compare::sexp;
+pub use compare::compare_document;