(CygbuildBootVariablesGlobalMain): CYGBUILD_INSTALL_IGNORE add *MANIFEST*

Signed-off-by: Jari Aalto <jari.aalto@cante.net>
libcheck.sh (CygbuildCygcheckLibraryDepSourcePython): Do not warn about os.rename any longer

Signed-off-by: Jari Aalto <jari.aalto@cante.net>