ext\neon\gstneonhttpsrc.c: Include unistd.h only if _HAVE_UNISTD_H is defined

ext\neon\gstneonhttpsrc.c: Include unistd.h only if _HAVE_UNISTD_H is defined

Original commit message from CVS:
* ext\neon\gstneonhttpsrc.c:
Include unistd.h only if _HAVE_UNISTD_H is defined
* gst\mpegvideoparse\mpegvideoparse.c:
Use G_GUINT64_CONSTANT GLIB macro for constant
* sys\dshowsrcwrapper\gstdshowaudiosrc.c:
* sys\dshowsrcwrapper\gstdshowvideosrc.c:
* sys\dshowdecwrapper\gstdshowaudiodec.c:
* sys\dshowdecwrapper\gstdshowaudiodec.h:
* sys\dshowdecwrapper\gstdshowdecwrapper.c:
* sys\dshowdecwrapper\gstdshowdecwrapper.h:
* sys\dshowdecwrapper\gstdshowvideodec.c
* sys\dshowdecwrapper\gstdshowvideodec.h:
Add a DirectShow decoder wrapper.
* win32\MANIFEST:
Add new win32 files to MANIFEST
* win32\vs6\gst_plugins_bad.dsw:
* win32\vs6\libgstdshow.dsp:
* win32\vs6\libgstdshowdecwrapper.dsp:
* win32\vs6\libgstflv.dsp:
Add new projects to bad workspace