Gqrx SDR 2.16

• New: Restore AM & AM-Sync settings between sessions.
• New: Set/get audio gain via remote control.
• New: Only show bookmarks for active tag groups in the panadapter.
• Fixed: Loading of narrow FM tau setting.
• Fixed: Crash when adding or removing bookmark tags.
• Fixed: Redraw bookmarks immediately after changes.
• Fixed: DX cluster spots fail to expire around midnight.
• Fixed: AGC sensitivity bug introduced in version 2.15.10.
• Improved: Rendering of frequency control and S-meter on some high-DPI screens.
• Removed: Support for GNU Radio 3.7.