enable opengl by default on windows

Change-Id: I04cd67cce88563c0e1d82af984ccd3e6516b69cb
fix invalid memory access in dx bitmap code

Change-Id: If3a495ab2db068f37dcee184e61c0c1e66f09666
clean configure.ac enable-opengl for windows

It works now and should get the same treatment as the linux version.

Change-Id: I382cc7cae9358ce26e0c2d85acc6a67e991d8118