Fixes BHV-13000

## Issue
Specifying a value for increment in the slider sample breaks spotlighting right because the increment value is set as a string and + performs string concatenation instead of arithmetic.

## Fix
Parse values from inputs to integers

Enyo-DCO-1.1-Signed-off-by: Ryan Duffy <ryan.duffy@lge.com>
I think we need to specify the radix here too. :)