ENYO-1741: adding two messages in the top of the panel "Phonegap Build" to display the status of the connection to the Phonegap account.

There are three status :
The user is authentified : the AppId label and the AppId input are displayed.
Ares is processing the authenfication action : the message "Looking for Phonegap account data ..." is displayed.
The authenfication action failed : the messsage "Sign-in is required" is displayed.
Merge branch 'ENYO-1741' of github.com:enyojs/ares-project into ENYO-1741