Adds the ability to use a specific prefix and/or suffix on replay buffer
filenames to distinguish them from normal recordings. Defaults to
having the prefix "Replay".
Replay buffer and recording should be separate in case the user wants to
start recording from a specific point rather being forced to reconfigure
for regular recording.
Creates a new button on the main window below the recording button for
turning on/off the replay buffer.
QScreen::availableGeometry() does not return the full screen size on X11
if areas of the screen are reserved by the window manager. In this case
the full screen projector does not cover the whole screen. Using
QScreen::geometry() instead fixes this issue.
All of the monitor discovery logic can be implemented with Qt. This
change removes all the x11 implementations in favor of Qt and removes a
fair amount of platform specific code.
