Prettified things a little bit, also show xmpp connection status

app/src/main/java/nl/dobots/imbusy/ContactsActivity.java

app/src/main/java/nl/dobots/imbusy/DeviceSelectActivity.java

...rc/main/java/nl/dobots/imbusy/DeviceSettingsActivity.java

app/src/main/java/nl/dobots/imbusy/ImBusyApp.java

app/src/main/java/nl/dobots/imbusy/MainActivity.java

app/src/main/res/layout/activity_contacts.xml

app/src/main/res/layout/activity_device_select.xml

app/src/main/res/layout/activity_device_settings.xml

app/src/main/res/layout/activity_main.xml

app/src/main/res/values/strings.xml

app/src/main/res/values/strings_activity_login.xml