Mer: Fix MerVirtualBoxManager singleton implementation

Signed-off-by: Martin Kampas <martin.kampas@jolla.com>
Mer: Do not freeze during VM startup

Starting a VM (just the VM, not the OS inside) normally takes a while -
unless a message window is open by VirtualBox at VM start time waiting
for the user to respond.

Signed-off-by: Martin Kampas <martin.kampas@jolla.com>
UpdateInfo: Do not crash randomly when activating timers

Fixes QTCREATORBUG-11262

Signed-off-by: Martin Kampas <martin.kampas@jolla.com>
Merge pull request #24 from martyone/next

Fix crashes caused by UpdateInfo and more