rewrite demandload module to be more flexible. performance not affected. old demandload module could only import top-level modules like os and sys. with rewrite, all of following syntax is emulated perfectly: import foo, bar foo bar import foo.bar.quux foo.bar.quux from foo.bar import quux, blurfl foo.bar:quux,blurfl only thing missing is "import foo as bar". also, namespace clashes between placeholder object and demand loaded module are no longer possible.