Almost.
This works on windows and linux with different folder names (e.g. AnacondaV2 folder name works just fine):
```python
package_name = os.path.dirname(__file__).rsplit(os.path.sep, 3)[1]
ico_path = 'Packages/' + package_name + "/gutter_mark_themes/{theme}-{type}.png"
```

I can not use `os.path.join` to create icon path, that does not work on windows, since it uses `\` as path separator and sublime requires `/`.

I will add this change to next commit.