* Add ability to repeat motion with ,/;
* Add ability to disable bindings
* Change motions to +/-

This plugin adds support for motions and text object based around
subwords. A "subword" is a constituent word of a larger "metaword"
in some case format. For examle "camel" is a "subword" of the "metaword"
"camelCase" or "camel_case".

The text objects added are

* `i-` the inner subword. For this would match something like
  "[camel]_case" or "[camel]Case"
* `a-` around the subword. This distinction only matters for snake_case,
  where the match would be "[camel_]case". For camelCase, this is the
  same as `i-`.
* `i_`/`a_` like the above, but interpret ambiguous metawords as
  snake_case. For example, the metaword ThisIs_AnExample is ambiguous
  because it's both snake_case and camelCase. `i-`/`a-` interpet it as
  camelCase, but `i_`/`a_` interpet it as snake_case.

    ThisIs_AnExample
      ^

    i- === [This]Is_AnExample
    a- === [This]Is_AnExample
    i_ === [ThisIs]_AnExample
    a_ === [ThisIs_]AnExample

The motions added are

* `M--` (Meta + hyphen) Move forward one subword
* `M-_` (Meta + underscore) Move backward one subword.