Non-standard paths

make_ver and at least one place in the Makefile will fail with an unintuitive message if the current working PATH contains spaces. This needs to be be addressed.

Similarly, on some exotic UNIX systems, when operating in the POSIX or C locale, make will fail if paths, such as the current working directory, contain Unicode characters. This is a rare case but if we can determine the systems that exhibit this behavior, we should detect them and issue a warning.