Add some flexibility in the property sheets for one building GTK+ that it
also searches for a settable installation path of Python, in addition to
searching the PATH for an installation of the Python interpretor. This
currently defaults to Python 2.7.x, which is normally installed in
c:\python27 on Windows by default. Also tell people in the README.txt's
for the Visual Studio builds
Add a utility project to get config.h and gdkconfig.h from their *.h.win32
(or win32_broadway, if applicable) counterparts, using custom build rules,
so that these "generated" files can also be removed on clean and
"regenerated" upon update. This also enables the removal of configs in
certain projects that isn't really needed as a result.
Also update and merge the projects and property sheets to include a single
property sheet that it needs, which will then in turn include the other
property sheets that is needed, so that things are cleaner.
Updates to the Visual Studio 2010 projects will follow later.
