Add parameters to set the ADB server socket via viewclient.connectToDeviceOrExit().
Add parameters to set the ADB server socket via viewclient.connectToDeviceOrExit().

The host and port were previously the default ones computed in adbclient by
reading the ANDROID_ADB_SERVER_HOST and ANDROID_ADB_SERVER_PORT environment
variables. Client code could customize the connection by setting the connect()
function via the eponymous argument but then the AdbClient.hostname and
AdbClient.port properties would be out of sync.

So the only way to use another host/post was to have the environment variables
defined, which meant to set os.environ before importing the ViewClient package
when these values must be set programmatically.

dtmilano/AndroidViewClient,dtmilano/AndroidViewClient,dtmilano/AndroidViewClient