This supports JIRA ENYO-3643
The default value for phonegap version has been changed to 3.1.0.
The value 3.0.0 has been removed as it is no longer officially supported (see [PhoneGap build documentation](http://docs.build.phonegap.com/en_US/3.1.0/configuring_preferences.md.html#Preferences "phonegap doc")
Merge branch 'master' of github.com:enyojs/ares-project into ENYO-3643
Merge pull request #715 from enyojs/ENYO-3643

ENYO-3643: default phonegap version should be 3.1.0