Integration of qmlfmt linting tool (#1462)

* Add first qmlfmt support

* Add GetCommand() function

- pass --error/-e option

* Add handle unittest

- fix pattern regex
- store col as integer

* Update docs

* Add command callback unit test

README.md

@@ -140,7 +140,7 @@ formatting.
 | Pug | [pug-lint](https://github.com/pugjs/pug-lint) |
 | Puppet | [puppet](https://puppet.com), [puppet-lint](https://puppet-lint.com) |
 | Python | [autopep8](https://github.com/hhatto/autopep8), [flake8](http://flake8.pycqa.org/en/latest/), [isort](https://github.com/timothycrosley/isort), [mypy](http://mypy-lang.org/), [prospector](http://github.com/landscapeio/prospector), [pycodestyle](https://github.com/PyCQA/pycodestyle), [pyls](https://github.com/palantir/python-language-server), [pylint](https://www.pylint.org/) !!, [yapf](https://github.com/google/yapf) |
-| QML | [qmllint](https://github.com/qt/qtdeclarative/tree/5.11/tools/qmllint) |
+| QML | [qmlfmt](https://github.com/jesperhh/qmlfmt), [qmllint](https://github.com/qt/qtdeclarative/tree/5.11/tools/qmllint) |
 | R | [lintr](https://github.com/jimhester/lintr) |
 | ReasonML | [merlin](https://github.com/the-lambda-church/merlin) see `:help ale-reasonml-ols` for configuration instructions, [ols](https://github.com/freebroccolo/ocaml-language-server), [refmt](https://github.com/reasonml/reason-cli) |
 | reStructuredText | [alex](https://github.com/wooorm/alex) !!, [proselint](http://proselint.com/), [redpen](http://redpen.cc/), [rstcheck](https://github.com/myint/rstcheck), [vale](https://github.com/ValeLint/vale), [write-good](https://github.com/btford/write-good) |