Use the same Linux paths, as the cron implementations available on
the Hurd as usually the same as Linux.

- fix test for equality of compound ID's, they are case insensitive you know

faster unique_id

better error reporting when loading dictionary

added couple of comparison operators to sym_op class

As argument rhs is not being used in that equals (should the equals function always return false), I added that flag so the compiler skips that warning.