Icon mapping for OpenWeather codes 803 & 804

[dtenglish]

The api mapping for OpenWeather doesn't correctly adjust for day/night on codes 803 and 804, instead pointing to same icon as the neutral mapping.

Neutral:

.wi-owm-803:before {
  content: "\f013";
}
.wi-owm-night-804:before {
  content: "\f013";
}

Day:

.wi-owm-day-803:before {
  content: "\f013";
}
.wi-owm-day-804:before {
  content: "\f013";
}

Night:

.wi-owm-night-803:before {
  content: "\f013";
}
.wi-owm-night-804:before {
  content: "\f013";
}

I believe day should be using f002 and night should be using f086.

Additionally, for consistency with the night icon, I believe the mapping for .wi-owm-day-801 should be changed to icon f00c.