NameParser validation is not correct

E.g:

``` java
  if (!VALID_REPO_PATTERN.matcher(name).matches()) {
            throw new InvalidRepositoryNameException(String.format(
                    "Invalid repository name (%s), only [a-z0-9-_.] are allowed", name));
        }
```

Disallows names with hyphens, which _are_ allowed.

Correct set seem to be here:

https://github.com/docker/docker/blob/master/registry/v2/regexp.go
