Mac OS X: Further update to the DMG template image

It seems on Lion the folder background image is missing while on earlier
OS X versions it is displayed fine. Still no idea why that is happening...
Mac OS X: Another attempt to fix DMG template for Lion

Tried to modify template background picture with a script, but to
no avail.
Mac OS X: Redid DMG template on Lion

Perhaps the template will work better when it has been created on Lion.
Sync view pitch updates to sharp ticks

Player camera yaw angles were already updated only at
sharp ticks. However, pitch angles were not.

Now both angles are treated the same way.
Ensure mouse gets trapped and main window is active

If mouse is enabled, it will get trapped immediately after the main window
is shown. Also, the main window is explicitly activated and raised.
de::Time: Added a sleep() method for de::Time::Delta

Blocking the thread for a given time period.
Fixed: Threads can't wait on themselves, use a proper sleep instead

Sleep a thread with de::Time::Delta::sleep().
Timer: Cleaned up shutdown

The mutex handle wasn't zeroed at shutdown, making it possible
for someone to attempt to lock it afterwards.
Fixed: Fatal error during busy mode (e.g., due to focus being lost)

The busy worker wasn't being stopped properly when an error occurred.
The busy error message is now copied into an independent buffer so it
persists after the worker is gone.

Removed an unnecessary fatal error in FI_PrivilegedResponder().
Win32: Tweaked widget sizing after mode switches

It appears on Windows a visible fullscreen QWidget does not update its geometry
when the display mode changes, so in this situation we'll briefly switch it to
normal show mode and then back to fullscreen mode.

Todo: Check if this approach works on OS X as well.
Cleanup: Removed frame counter used only for timedemo

In the future this should integrate into the main frame/FPS counter.
Added: Variables "vid-fsaa" and "vid-vsync"

FSAA and vsync can be toggled at runtime with the new vid-fsaa and
vid-vsync variables. The command line options -nofsaa and -novsync
can be used to permanently disable FSAA and vsync, respectively.

Also, when the mouse is trapped in a window, all GL updates will be
timed manually to match the requested maximum refresh rate. This
will only have an effect if refresh-rate-maximum is less than the vsync
rate.
Win32: Always request window updates via windowing system events
CanvasWindow|Fixed: Canvas GL init after recreation

The GL context needs to be activated during the init of the
new Canvas, and a manual update may be required.
Fixed: Randomly stalled main loop callback execution

The waitingForDraw variable was not robust enough for all situations.
Sometimes it causing updates to stop completely (e.g., after switching
from busy mode).
Debug: Threads must not wait on themselves
qmake|Unix: Always link against libX11
Fixed: Fatal errors from worker thread

The busy worker thread will now start sleeping indefinitely when an
error occurs. The main thread will kill it and proceed to shut down
the engine after showing the error dialog.
Cleanup: Removed debug prints to stderr
de::LogBuffer|Win32: Output log entries with QDebug

Allows capturing the output in the IDE.