gtk-doc-windows: create dirs if they don't exist
gtk-doc-windows: create dirs if they don't exist

BigBrother-International/gst-cerbero,AlertMe/cerbero,justinjoy/cerbero,ikonst/cerbero,jackjansen/cerbero-2013,brion/cerbero,cee1/cerbero-mac,freedesktop-unofficial-mirror/gstreamer__cerbero,lubosz/cerbero,brion/cerbero,multipath-rtp/cerbero,shoreflyer/cerbero,ylatuya/cerbero,brion/cerbero,ford-prefect/cerbero,freedesktop-unofficial-mirror/gstreamer-sdk__cerbero,nirbheek/cerbero-old,jackjansen/cerbero-2013,sdroege/cerbero,freedesktop-unofficial-mirror/gstreamer-sdk__cerbero,ramaxlo/cerbero,EricssonResearch/cerbero,freedesktop-unofficial-mirror/gstreamer__cerbero,jackjansen/cerbero,ramaxlo/cerbero,davibe/cerbero,freedesktop-unofficial-mirror/gstreamer__sdk__cerbero,AlertMe/cerbero,freedesktop-unofficial-mirror/gstreamer__cerbero,flexVDI/cerbero,freedesktop-unofficial-mirror/gstreamer__cerbero,brion/cerbero,ford-prefect/cerbero,GStreamer/cerbero,centricular/cerbero,jackjansen/cerbero-2013,centricular/cerbero,davibe/cerbero,lubosz/cerbero,fluendo/cerbero,nicolewu/cerbero,ramaxlo/cerbero,sdroege/cerbero,centricular/cerbero,AlertMe/cerbero,ylatuya/cerbero,BigBrother-International/gst-cerbero,atsushieno/cerbero,EricssonResearch/cerbero,davibe/cerbero,nirbheek/cerbero,davibe/cerbero,GStreamer/cerbero,freedesktop-unofficial-mirror/gstreamer__sdk__cerbero,justinjoy/cerbero,ikonst/cerbero,nirbheek/cerbero-old,multipath-rtp/cerbero,cee1/cerbero-mac,GStreamer/cerbero,sdroege/cerbero,freedesktop-unofficial-mirror/gstreamer__sdk__cerbero,shoreflyer/cerbero,nzjrs/cerbero,ramaxlo/cerbero,ford-prefect/cerbero,cee1/cerbero-mac,justinjoy/cerbero,flexVDI/cerbero,BigBrother-International/gst-cerbero,AlertMe/cerbero,superdump/cerbero,superdump/cerbero,freedesktop-unofficial-mirror/gstreamer-sdk__cerbero,flexVDI/cerbero,atsushieno/cerbero,jackjansen/cerbero,lubosz/cerbero,ylatuya/cerbero,centricular/cerbero,OptoFidelity/cerbero,freedesktop-unofficial-mirror/gstreamer__sdk__cerbero,multipath-rtp/cerbero,nicolewu/cerbero,ikonst/cerbero,BigBrother-International/gst-cerbero,jackjansen/cerbero,OptoFidelity/cerbero,atsushieno/cerbero,freedesktop-unofficial-mirror/gstreamer-sdk__cerbero,superdump/cerbero,fluendo/cerbero,sdroege/cerbero,nicolewu/cerbero,nzjrs/cerbero,brion/cerbero,fluendo/cerbero,nzjrs/cerbero,GStreamer/cerbero,jackjansen/cerbero-2013,EricssonResearch/cerbero,centricular/cerbero,atsushieno/cerbero,nzjrs/cerbero,OptoFidelity/cerbero,ikonst/cerbero,ford-prefect/cerbero,superdump/cerbero,ikonst/cerbero,fluendo/cerbero,flexVDI/cerbero,justinjoy/cerbero,shoreflyer/cerbero,nzjrs/cerbero,OptoFidelity/cerbero,multipath-rtp/cerbero,fluendo/cerbero,BigBrother-International/gst-cerbero,sdroege/cerbero,flexVDI/cerbero,EricssonResearch/cerbero,atsushieno/cerbero,lubosz/cerbero,nirbheek/cerbero,cee1/cerbero-mac,jackjansen/cerbero-2013,nirbheek/cerbero,EricssonResearch/cerbero,ramaxlo/cerbero,shoreflyer/cerbero,nirbheek/cerbero-old,shoreflyer/cerbero,nirbheek/cerbero,nirbheek/cerbero-old,GStreamer/cerbero,AlertMe/cerbero,jackjansen/cerbero,freedesktop-unofficial-mirror/gstreamer-sdk__cerbero,ylatuya/cerbero,multipath-rtp/cerbero