configure: Fix Python configure checks to work with all Python versions between 2.7 and 3.3
configure: Fix Python configure checks to work with all Python versions between 2.7 and 3.3

freedesktop-unofficial-mirror/gstreamer__gst-python,pexip/gst-python,pexip/gst-python,lubosz/gst-python,lubosz/gst-python,GStreamer/gst-python,pexip/gst-python,lubosz/gst-python,GStreamer/gst-python,GStreamer/gst-python,freedesktop-unofficial-mirror/gstreamer__gst-python,freedesktop-unofficial-mirror/gstreamer__gst-python