• Fix : t/16-huf.t failures on Solaris and FreeBSD caused by not
  updating mg->mg_ptr after Renew-ing it on dispell.
  
• Fix : Undefining MGf_DUP caused the wizard's magic to be wrongly
  initialized. MGf_DUP now appears as true from the user point of
  view, but the dup callback isn't actually set.
  
• Fix : Warnings with blead due to copy callbacks now taking an I32 (API
  change #33256).
  
• Fix : vmg_svt_val() and vmg_uvar_del() aren't required if no uvar
  magic is available.
  
• Tst : Tests now output the version of optional modules loaded.