Use RJS to render edit note feature.

Before:

```
Rendered projects/notes/_note.html.haml (27.9ms)
Rendered projects/_zen.html.haml (0.3ms)
Rendered projects/notes/_hints.html.haml (0.7ms)
Rendered projects/_md_preview.html.haml (3.9ms)
Rendered projects/notes/_edit_form.html.haml (6.9ms)
Rendered projects/notes/_note.html.haml (17.7ms)
Rendered projects/_zen.html.haml (0.3ms)
Rendered projects/notes/_hints.html.haml (0.6ms)
Rendered projects/_md_preview.html.haml (3.4ms)
Rendered projects/notes/_edit_form.html.haml (7.0ms)
```

After:

```
Rendered projects/notes/_note.html.haml (13.8ms)
Rendered projects/notes/_note.html.haml (7.1ms)
Rendered projects/notes/_note.html.haml (9.5ms)
Rendered projects/notes/_note.html.haml (8.5ms)
```

This change reduce at least 6ms * N ('N' - number of notes).

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Makes use of Capybara methods that wait. Hopefully this will fix the
random timing-related failures of this step.

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

There's a naming conflict between Capybara and rspec-matchers which both
define the `all` method.

See https://github.com/jnicklas/capybara/issues/1396

Closes #1321

Fix bug where error messages from Dropzone would not be displayed on the issues page

Closes #1258

Make the following changes to deal with new behavior in Rails 4.1.2:

* Use nested resources to avoid slashes in arguments to path helpers.

- do not add Feature to feature titles
- titleize feature titles
- put steps on the same path as .feature files
- make feature titles match their path

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Add sleep in tests to prevent random failing when next test starts before ajax requests for old one in progress