Added storing and restoring of currently bound texture, clear color
and framebuffer when recreating the FBOs. When FBOs are created
they are now created with new id's to avoid changing FBOs and textures
that are being used in the CanvasRenderNode.

Change-Id: Ib1901a0031f4d7ee16b08bcd6fc4fac91a25fabe
Reviewed-by: Tomi Korpipää <tomi.korpipaa@digia.com>
Reviewed-by: Pasi Keränen <pasi.keranen@digia.com>