MUMessagesDatabase: don't add nil (misparsed) data URLs to the imageDataArray.
MumbleKit: sync.
BuildConfig: flip the Opus switch.
MUApplicationDelegate: enable Opus unconditionally.
BuildConfig, Source: get rid of OPUS_ENABLED flag.
MUAudioSidetonePreferencesViewController: add and hook up.
MUAudioTransmissionPreferencesViewController: remove PTT show-in-view configuration.
MUApplicationDelegate, MUServerViewController: always show PTT-button in server view.
MUChannelViewController, MUServerViewController: increase doff-state alpha of PTT button.
Info.plist: bump version to 1.2.
MUServerRootViewController: remove channel view.
MUServerRootViewController, MUServerViewController: implement mode toggle in server view (triggered by Mumble icon tap).
MUServerRootViewController: adjust position of Messages badge.
MUAdvancedAudioPreferencesViewController: fix preprocessing on/off switch.
MUAudioTransmissionPreferencesViewController: allow entering the VAD config view controller.
MumbleKit: sync.
MUMessagesViewController: basic local notifications for messages.
MUApplicationDelegate, MUConnectionController, MUMessagesViewController, MUServerRootViewController: make app badge reflect number of unread messages.
MUMessagesViewController: show correct notification text  when received messages are empty, or only contain images.
Mumble.xcodeproj, MUApplicationDelegate: make app universal, use phone welcome screen to boot.