SConstruct : `additionalFiles` can't be directories.
SConstruct : `additionalFiles` can't be directories.

- The `INSTALL` override used on Windows for installing symlinked files can only handle files, not directories.

andrewkaufman/gaffer,hradec/gaffer,andrewkaufman/gaffer,johnhaddon/gaffer,andrewkaufman/gaffer,johnhaddon/gaffer,GafferHQ/gaffer,GafferHQ/gaffer,andrewkaufman/gaffer,johnhaddon/gaffer,johnhaddon/gaffer,hradec/gaffer,hradec/gaffer,GafferHQ/gaffer,johnhaddon/gaffer,GafferHQ/gaffer,hradec/gaffer,hradec/gaffer,GafferHQ/gaffer,andrewkaufman/gaffer