Re-Added the certificate dialog

app/src/main/java/de/kuschku/libquassel/BusProvider.java

app/src/main/java/de/kuschku/libquassel/CoreConnection.java

app/src/main/java/de/kuschku/libquassel/QuasselClient.java

...a/de/kuschku/libquassel/events/ConnectionChangeEvent.java

...de/kuschku/libquassel/events/UnknownCertificateEvent.java

...in/java/de/kuschku/libquassel/ssl/CertificateManager.java

...n/java/de/kuschku/libquassel/ssl/QuasselTrustManager.java

...e/kuschku/libquassel/ssl/UnknownCertificateException.java

...schku/quasseldroid_ng/service/ClientBackgroundThread.java

...va/de/kuschku/quasseldroid_ng/service/QuasselService.java

...java/de/kuschku/quasseldroid_ng/ui/chat/MainActivity.java

...ain/java/de/kuschku/quasseldroid_ng/ui/chat/Settings.java

...uschku/quasseldroid_ng/ui/chat/fragment/ChatFragment.java

...hku/quasseldroid_ng/ui/chat/fragment/LoadingFragment.java

...java/de/kuschku/quasseldroid_ng/ui/setup/AccountItem.java

...uschku/quasseldroid_ng/ui/setup/AccountSetupActivity.java

...e/kuschku/quasseldroid_ng/ui/setup/CreateAccountItem.java

...u/quasseldroid_ng/ui/setup/slides/AccountSelectSlide.java

...n/java/de/kuschku/quasseldroid_ng/ui/theme/ThemeUtil.java

...va/de/kuschku/util/MeaningfulConnectionErrorProvider.java