ENYO-3504: fix the regression by doing the test between the picker item & the value of project.json file on the "content" attribute of the picker item instead of "value" attribute.

This regression is due to the evolution of ENYO Pilot.
ENYO-3504: override the activatePickerItemByContent() function for the kind "Phonegap.ProjectProperties.SDKVersionRow".
ENYO-3504: fix space/tab issues
Merge pull request #646 from enyojs/ENYO-3504

ENYO-3504: fix the regression on Phonegap build Panel concerning the initialization of the picker.