Inconsisten specification of contains

The `contains` is not defined consistently:
1. in https://github.com/persvr/rql/blob/master/specification/draft-zyp-rql-00.html#L457 as
```contains(,)```
2. in https://github.com/persvr/rql/blob/master/specification/draft-zyp-rql-00.xml#L185
```contains(,)```
3. in README.md
```contains(,)```
4. if I read the implementation correctly https://github.com/persvr/rql/blob/master/js-array.js#L59 it does support query/expression.

Could you pls correct draft-zyp-rql-00.html so that the definition of contains is consistent?
Also does `query` and `expression` have interchangeable meaning here? Would be clearer if you sticked to one of them in all documents or at least within the README.md.