Improve compact diff API (#24)

* Remove is_binary from API

* Format

* Rename file

* Test with more feature combinations

* Don't depend on serde for wasm

* Fix lint & tests

* Don't unwrap to MAX number

* Expose undiff to JS

* Add undiff tests

* Lint

* Change name

src/utils.rs

@@ -1,6 +1,5 @@
 pub mod common_prefix_len;
 pub mod common_suffix_len;
 pub mod find_longest_prefix_contained_within;
-pub mod is_binary;
 pub mod myers_diff;
 pub mod string_builder;