remove global variable

Change-Id: Ie5f55feb39798dff27e0c6b41d5b88b6e9bf19bc
provide the OpenGL window

This approach looks much better. We get size and position correct
without much work and can easily plug the window into the sc window
hierarchy.

We still have a crash on exit as the ScGridWindow goes out of scope and
the SystemChildWindow is still alive. We need to fix it and bind the
lifecycle of the SystemChildWindow to ScGridWindow.

Another open item is the OpenGL context work. Right now it looks like
the best way forward is to create a subclass of SystemChildWindow that
contains the OpenGLContext.

Change-Id: Ie0a74531e1b818cea92912345464c8fa219bbae2
fix the OpenGL offscreen rendering a bit

Change-Id: I1f11cdff0de48e3281a58aec9ea37a78c637195e
add new window that contains OpenGL context

Change-Id: I81ce3581942d03785809d728b6b54b570899bcdc
avoid linking against the OpenGL libs when only using the window

This lets us avoid to link libsclo against all the OpenGL libraries and
only link against libvcl_opengl. Only code actually using the context
will need to link against the OpenGL libs.

Change-Id: Ia47f4c651702a7fb8517073cda6fb113e7e26e50
let us use the new OpenGLWindow

Change-Id: I5cbab0aa1707513b62f7a9958fac013b3beb2dcb
the rendering is working on-screen

I can't believe that I finally see something on the screen.

Change-Id: Ic374c8a0d0fa5050b0701a5553136759c9c7602c
the temporary context can finally die

Change-Id: I7dec2772000e25c4bd23f21b61dbd835ef9397cf
let us pass the window to get the size correct

Change-Id: I8bd8a319e67cdcf7266d3c8f86d1bf132163d665
set the size to context and renderer before rendering

Change-Id: I2945a7b8647d0a40270b1e65cde2a0eb936ab1d1
fix crash when canceling the chart wizard

Change-Id: Iebd9db279e9db22bc273509cf480737d7c7a1dd6
provide bar color for 3D OGL chart

Change-Id: Ia41748cabba89a0257c62f66a280810adc56960e
hide OpenGLWindow in normal charts

Change-Id: Ie45a910d2b99b7644a8055476aa191ef8a724d38
fix crash on exit

Change-Id: I31374684a09f1b056154efcaa5c7dfe73bcc1a61