SSH: Don't allow connectToHost() while already connecting/connected.

Also fix callers potentially violating this policy.

Change-Id: I630f1c544885df93a81e217e792363c0c2314108
Reviewed-on: http://codereview.qt.nokia.com/1186
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Daniel Teske <daniel.teske@nokia.com>

src/plugins/remotelinux/remotelinuxapplicationrunner.cpp

@@ -105,7 +105,8 @@ void RemoteLinuxApplicationRunner::start()
         handleConnected();
     } else {
         emit reportProgress(tr("Connecting to device..."));
-        m_connection->connectToHost();
+        if (m_connection->state() == Utils::SshConnection::Unconnected)
+            m_connection->connectToHost();
     }
 }