Jit64: remove dead code
IPCHLE: improve HLE timing.

This change attempts to make calls to WII_IPC_HLE_Interface::Update()
more consistent.  We should be calling it whenever there is something we
can pop from a queue, and this patch does that.

DeviceUpdate() now works independently of Update(): it's now just a periodic
timer for devices which need to regularly update state.

With this change, we need a non-zero default delay for IPC replies because
replies are popped off the queue much more aggressively.

This fixes launching channels from the the System Menu.
IPCHLE: clean up spelling.
Remove EmuWindow.

All it did was raise complexity.
Fix OpenGL video backend when using "render to main" on Windows.
Don't create a Panel for a seperate render window.

Instead of setting RenderParent to null and raising complexity RenderFrame can be its own parent.
Remove CPanel.

Let the RenderFrame handle those messages.
Remove wxTAB_TRAVERSAL style from RenderFrame.
Fix RendererHasFocus().
Remove g_pWindowHandle.

Now that the EmuWindow is gone we don't need the global anymore. The Host should provide a window handle for the renderer.
Update documentation.