Implement SSL verification and whitelisting

...main/java/de/kuschku/quasseldroid/service/AsyncBackend.kt

...in/java/de/kuschku/quasseldroid/service/QuasselService.kt

...hku/quasseldroid/ssl/BrowserCompatibleHostnameVerifier.kt

...va/de/kuschku/quasseldroid/ssl/QuasselHostnameVerifier.kt

...n/java/de/kuschku/quasseldroid/ssl/QuasselTrustManager.kt

...chku/quasseldroid/ssl/custom/QuasselCertificateManager.kt

...kuschku/quasseldroid/ssl/custom/QuasselHostnameManager.kt

...main/java/de/kuschku/quasseldroid/ui/chat/ChatActivity.kt

...kuschku/quasseldroid/util/helper/X509CertificateHelper.kt

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

app/src/main/res/values-de/strings_error.xml

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

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

.../java/de/kuschku/libquassel/connection/ConnectionState.kt

...n/java/de/kuschku/libquassel/connection/CoreConnection.kt

...rc/main/java/de/kuschku/libquassel/connection/Features.kt

...java/de/kuschku/libquassel/connection/HostnameVerifier.kt

.../java/de/kuschku/libquassel/connection/MessageRunnable.kt

...kuschku/libquassel/connection/QuasselSecurityException.kt

...in/java/de/kuschku/libquassel/connection/SocketAddress.kt