improve OpenGL rendering engine selection for Windows backend

Change-Id: Ibcf520aac1441e5ce86b83372061550f8957ab17
don't try to use OpenGL for printing

Change-Id: I88403bcb5b1974deba237c497885d3793a29315c
init the OpenGL context in the windows backend

Change-Id: Ic4fb491c95170639015a4452f355354ad01612bc
forgot to remove the env variable based OpenGL setting

Change-Id: Ib4d0c4730eceac483bb179ce4e75fe555bba91fa