add uniquely-named class to IntegerPicker flyweight repeater

The previously generic 'list' class conflicting with the sampler app
and therefore likely to conflict with third-party apps.
Merge pull request #1536 from enyojs/CMB-602-ryanjduffy

Fixes CMB-1339

Looks good!

Reviewed-by: Aaron Tam (aaron.tam@lge.com)