[kcalc] KF5 port: replace KLocale::formatNumber() with custom code
Review Request #120357 - Created Sept. 24, 2014 and submitted
To remove the last bits of KDELibs4Support in kcalc port, I had to replace KLocale::formatNumber() with a custom function, because I found no way to format arbitrary precision numbers with QLocale.
The groupSize is hardcoded to 3, I did not find a simple way to query QLocale.
The code also replaces all digits with locale digits; not sure if the original KLocale code did the same and if this should be applied to kcalc.
Tested with german locale, which has '.' as groupSeperator, and ',' as decimalPoint.