WINTERMUTE: Fix bug that prevented the opaque and binary blit speedups from working.
WINTERMUTE: Special-case FMV-handling to not fill the screen with background color.

If we have only one thing being drawn, and that is opaque, we can
skip filling the render surface with background color.
This shaves another few wasted cycles of the FMV playback. (Since we
now don’t have to write the entire render surface TWICE).

This reduces the time spent in drawTickets() to ~60% of what it was before.
WINTERMUTE: Avoid using Graphics::copyFrom to copy FMV-frames.

copyFrom frees and reallocates the surface for every update, as long
as the dimensions and format stay the same, we can do with just a
memcpy.

This gives a tiny improvement in the update-part of the Theora-player
(on the order of a bit more than 1 second saved total in the 1:28 long
J.U.L.I.A.-intro)
WII: Implement changes needed by DevKitPPC R26 and later

This changes makes ScummVM compilable with newer versions of DevKitPPC. ScummVM can be linked against the original libogc and libfat. That makes some newer WiiMotes work, improves audio-/video-playback and contains various improvements.
FULLPIPE: Implement sceneHandler38_hammerKick()
FULLPIPE: Implement sceneHandler38_point()
FULLPIPE: Implement sceneHandler38_propose()
FULLPIPE: Started implementation of sceneHandler38_animateAlcoholics()
WINTERMUTE: Enable Wintermute by default.
BUILD: Rename libunity support variable to "USE_UNITY" instead of "USE_TASKBAR_UNITY".

This makes it consistent with other library support variables.
BUILD: Auto detect taskbar support.

Formerly the taskbar support was *always* enabled except when the backend or
user specified that it should be disabled. This causes nasty crashes for
backends which do not have any taskbar support (like DC, Tizen and probably
more which simply did not disable it so far) when defaultErrorHandler was
called for example (Mass Add is also broken for those).
The SDL (and derived backends) worked around missing taskbar support by
simply faking a dummy taskbar implementation (but still claiming in configure
that we feature taskbar integration, ouch).

To avoid all non-SDL backends from manually specifying _taskbar=no I added
some auto detection code which simply only enables taskbar support in case
ScummVM is built on Win32 or libunity is present.
Merge pull request #413 from AReim1982/master

WII: Implement changes needed by DevKitPPC R26 and later
FULLPIPE: Complete sceneHandler38_animateAlcoholics()
Merge pull request #421 from lordhoto/taskbar-cleanup

BUILD: Taskbar Cleanup/Fixes
BUILD: Remove now superfluous _taskbar=no in Wii specific configuration.
OPENGL: Properly query for OpenGL errors.

There might be various error flags and we need to clear all of them to get
precise error results. Thus, we need to call glGetError in a loop to achieve
that.
Merge https://github.com/scummvm/scummvm