runApp and uninstall should use appId + install app if not installed on runApp user request

change remote-simulator-client runApp and uninstall methods to use appId
(an in the install method) and use the appId to check if the application
is already installed in the DOMApllicationRegistry.webapps on the b2g side.

If an app in not installed try to install and run it again.
on upgrade ensureXkeysUnique and leave apps to be lazily reinstalled by the run button (should fix #308)