[kcmkwin/kwindesktop] Implement valueFromText in a spinbox
If textFromValue is set, valueFromText must be.
A lot of other implemenetations were using parseInt() which fails at reading "3,000" due to the comma. Qt's fromLocaleString handles that but needs any text stripping.
This implementation isn't perfect, but really we need to work on a good upstream solution.
Edited by David Edmundson