Unicode parsing

[woble]

Files containing for example Chinese characters do not get parsed and the plugin produces an error similar to this:

UnicodeDecodeError: 'charmap' codec can't decode byte 0x9d in position 885: character maps to <undefined>

Easy way to fix this is to modify style_parser.py on lines 99 and 131 by adding encoding='utf8' to the open function.

Before:

 98            get_output_panel().set_name(file_path)
 99            with open(file_path, 'r') as f:
100                content = f.read()

After:

 98            get_output_panel().set_name(file_path)
 99            with open(file_path, 'r', encoding='utf8') as f:
100                content = f.read()

[subhaze]

I've merged @katerlouis PR, so this should hopefully be fixed.