require ExpandableIntegerPicker to be valued

Sync the default values between ExpandableIntegerPicker and IntegerPicker, refine bindings, eliminate unnecessary computed properties

Issue: ENYO-644
Enyo-DCO-1.1-Signed-off-by: Ryan Duffy (ryan.duffy@lge.com)
remove noneText from ExpandableIntegerPicker in samples

Enyo-DCO-1.1-Signed-off-by: Ryan Duffy (ryan.duffy@lge.com)
Merge pull request #1833 from enyojs/ENYO-644-ryanjduffy

Fixes ENYO-644

Reviewed-By: Derek Anderson (derek.anderson@lge.com) 
Integrated-By: Aaron Tam (aaron.tam@lge.com)