[mythtv] Extending mythweather units.

[Tim Phipps]

Hi All,
	Unfortunately I'm a middle aged English bloke so my preference of measurement 
units is completely mangled i. e. I work in Celsius and miles. I've hacked 
mythweather so it displays in my preferred units but I'd rather get a patch 
accepted into the source so I don't have to keep doing this so I've a few 
questions.

*) Would anyone else be interested in weird mixes of units?
*) if so what?

If there turns out to only be a few common mixes would it be OK to just add 
the to the list on the mythweather setting page and extend the SIUnits config 
setting to include the same?

That would be my preference. I can see a need for a fully customizable way to 
keep the current setting behaviour and have an override for each type of 
measurement (temp, speed, distance, pressure) so we don't have an ever 
growing list of styles but I don't know how that would work in the GUI or the 
config settings.

The actual code change look pretty simple, it just means splitting the 
convertData variable into four.

Cheers,
Tim.