fix how to run local tests
1/ make sure tests are running in english (from a ecma402 perspective)
2/ fix issue with use of NumberFormat in ProgressBar
remove underscore prefix from local variable.
Add unit test for fractionDigit. Fixes https://github.com/ibm-js/deliteful/issues/126
rework Slider
Slider: add unit tests
Slider: add functional tests
Slider: add samples