renamed osg::Image::pixelFormat(), internalTextureFormat(),dataType() to
osg::Image::getPixelFormat() etc. These changes are to bring it more
into line with the style of the rest of the OSG.
Updated the rest of the distribution to take account for these names changes.
osg::Texture. The values default to 0, and in this state they are
sizes of the glTexSubImage2D are taken from the source image size. This
allows the previous setup with no settings for subload size to work as
before.
much more of the core texture setup code. This largely invloved paramterizing
the applyImmediateMode, which has also been rename applyTexImage to reflect
its functionality better.
