Minimum translation percentage for Plasma 5 releases (second take)

[Albert Astals Cid]

After talking to a few people here in Randa about this issue, I come with an 
updated suggestion.

 * We ship all translations that are over a very low limit (say 5%)
 * When selecting a language in the language KCM that has less than 
$PERCENTAGE we show a dialog saying something like "Yo man, we know the 
translation of Plasma is not completed into this language, at the moment is at 
$CURRENTPERCENTAGE, you are still free to use it, and if you want to 
cotnribute to improve it, plz go to $SOMEURL" <- needs better wording

This way we set the expectations correctly, and people that prefer running 
translated even if it's just 23%, can do it, and people that think that 
running low-translated software is a SIN are told and can't complain anymore.

Probably we want to do this in other situations like startup of plasma after 
an upgrade, etc.

I'd suggest $PERCENTAGE to be quite high, something like 90% we used to have 
for kde-runtime.

What do you think?

Cheers,
  Albert