Added ability to change passwords

app/src/main/AndroidManifest.xml

...ain/java/de/kuschku/quasseldroid/dagger/ActivityModule.kt

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

...seldroid/ui/chat/passwordchange/PasswordChangeActivity.kt

...seldroid/ui/chat/passwordchange/PasswordChangeFragment.kt

.../ui/chat/passwordchange/PasswordChangeFragmentProvider.kt

...chku/quasseldroid/ui/coresettings/CoreSettingsFragment.kt

...e/kuschku/quasseldroid/ui/setup/core/CoreSetupActivity.kt

...c/main/java/de/kuschku/quasseldroid/util/TextValidator.kt

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

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

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

...ava/de/kuschku/libquassel/quassel/syncables/RpcHandler.kt