remember when controls are spotted on key down

Issue: ENYO-556
Enyo-DCO-1.1-Signed-off-by: Ryan Duffy (ryan.duffy@lge.com)
ENYO-556: Reset state upon keydown and only suppress [Enter] keypress.

Enyo-DCO-1.1-Signed-off-by: Aaron Tam <aaron.tam@lge.com>
ENYO-556: Update inline doc for new state variable

Enyo-DCO-1.1-Signed-Off-By: Gray Norton (gray.norton@lge.com)
Merge pull request #157 from enyojs/ENYO-556-ryanjduffy

Fixes ENYO-556

Reviewed-By: Aaron Tam (aaron.tam@lge.com)
Integrated-By: Gray Norton (gray.norton@lge.com)