Ticket 291: Require an error to be signalled if input files cannot be opened, no matter how

For with-input-from-file and call-with-input-file, R5RS just says that the file should exist. However, open-input-file requires an error to be signalled if the file cannot be opened, whether because it does not exist for some other reason like the lack of permissions. This inconsistency doesn't seem useful.

I propose changing with-input-from-file and call-with-input-file to also require an error to be signalled if the file cannot be opened. Every Scheme in my test suite, without exception, already implements this.