Weather Forecasting with descriptive temperatures

Updated the Greyhawk weather forecaster (1.2.0 -> 1.3.0) to use descriptive temperature ranges to ease gamemasters  description of the weather, and to have some quick clue of the effects it might have. The descriptive temperatures are based on ranges found on Dungeons & Dragons 3.5 Rules Compendium, and from where the compilation of effects (rules wise) can be checked if D&D 3.5 d20 rules are used.

Also, there is a new temperature column option named ‘Average’ to be shown in the forecast. It is ment to those who does not like knowing low and high temperatures, or to those who want to know the average temperature of low and high temperatures without calculating it.