Add needed entries in .def files.

Original commit message from CVS:
Patch by: Sergey Scobich <sergey dot scobich at gmail dot com>
* gst/gst.c:
* win32/common/libgstbase.def:
* win32/common/libgstreamer.def:
* win32/vs8/libgstbase.vcproj:
* win32/vs8/libgstcontroller.vcproj:
Add needed entries in .def files.
Use HAVE_UNISTD_H.
Rearrange def files in vs8 solutions. Fixes #366286.
6 files changed