Fixes to update to version 1.30.
Fix use of memset() and sprintf(); tidy formatting and comments.
Add support to BindHelp for mapping directory separators in filenames.
InProgress/SharedUnixLibrary.swi: Initial support for module.
Resolve compiler warnings when building DefMod
Ongoing work on resolving compiler warnings in the build tools.
Make DefMod respond to "--help" on the command line, in addition to "-help".
Files of zero length should still be loaded without error.