Small API breaks

[paroj]

• [ ] hide core movableobject factories
• [ ] unify mVertexProgramConstantFloatCount etc.
• [ ] make Texture::freeInternalResources private. unload does the same.
• [ ] drop OrientationMode (should be done transparently in rendersystem)
• [ ] move mManualBlendColours to RS that care
• [ ] move mVertexProgramBound etc to RS that care
• [ ] unify mActive*GpuProgramParameters
• [x] setCustomParameter should be Vector4f (also CustomParamsVec)
• [ ] drop DISPLAYNAME custom attribute. Can be queried from XDISPLAY
• [ ] move/ remove WorldFragmentType
• [ ] hide UnifiedHighLevelGpuProgram
• [ ] strip duplicate namespace for ImGuiSomething_FlagName flags (Python)
• [ ] remove ScriptLoader from classes in OgreMain
• [ ] hide lightsForShadowTextureLess, lightLess, materialLess
• [x] drop/ hide unused WORKQUEUE_*_REQUEST #2368
• [ ] ScriptCompilerListener::handleEvent *retValue should be **retValue or *&
• [ ] drop SimpleRenderable::mParentSceneManager (-> mManager)
• [x] Rectangle2D do not update bbox by default
• [ ] hide OGRE_SERIALIZER_VALIDATE_CHUNKSIZE
• [ ] drop VectorBase<dim, T>::operator=
• [ ] make RenderSystem::createRenderSystemCapabilities protected
• [ ] drop "uses_adjacency_information"
• [ ] drop MeshUpgrader interactive mode
• [ ] Controller<Real> should be Controller<float>
• [ ] make FrameTimeControllerValue::frameEnded/Started private (listener is impl detail)
• [ ] make createSceneNode non-virtual
• [ ] factor out LightClippingInfo-Cache (maybe)
• [ ] drop VertexBoneAssignment_s
• [ ] mCustomParameters / mCustomParams must be Vector4f
• [ ] drop BillboardChain::setDynamic
• [ ] hide BillboardChain::ElementList
• [ ] make "Stereo Mode" RS Option a boolean and get rid of StereoModeType
• [ ] apply USE_OGRE_FROM_FUTURE
• [ ] make _setBlendMaskData private
• [ ] move SPFM_DELETE_T to OgreDeprecated.h
• [ ] drop Animable::DEGREE type - Degree auto converts to Radian
• [ ] use Radian for LightSpotlight{Inner,Outer}Value
• [ ] remove AnimableObject protected methods