-In gio/Makefile.am, the name for one of the filters for capturing the
sources for the GIO VS Project Files is corrected.
-Remove the GIO source file items in the VS project files templates as
a result for this change, and move the entry of the "new"
gregistrysettingsbackend.c into the filter in gio/Makefile.am
Don't keep the lists of source files for libglib, libgobject and
libgio in the VS project files in addition to the canonical location,
the corresponding Makefile.am files.
Instead, generate the corresponding .vcproj files at make dist time
using the C preprocessor, from template files called .vcprojin. We
still list explicitly in the .vcprojin files some of the
Windows-specific source files, and the sources files of gnulib and
pcre.