Log Message:
Update to 1.6, changes:

 - Use the correct id(1) program.  Fixes PR pkg/40691

 - Avoid unprintable characters, some implementations of tr(1) have issues
   with them.  Instead go for what hopefully will be a unique string, as
   well as making use of shell parameter substitution.  Fixes PR pkg/42197

These changes combined make pkg_alternatives work correctly on Solaris.