allow creating multiple textures from the same video input file, with independent time, play/pause constrols
OgreVideoManager store mapping material name with texture objects and video clip getVideoClipByMaterialName() to get video clips by material name
function createVideoTexture() for creating video texture and return clip (instead of sequence call setInputName(), createDefinedTexture() and getVideoClipByMaterialName())
add protection against multiple initialise of OgreVideoPlugin