smf: switch to a tri-state for process-security properties true=on,false=off,nil=default

*** 76,95 ****
  .RE
  
  System default security-flags are configured via properties on the
  \fBsvc:/system/process-security\fR service, which contains a boolean property
  per-flag in the \fBdefault\fR, \fBlower\fR and \fBupper\fR, property groups.
! For example, to enable ASLR by default you would execute the following
! commands:
  .sp
  .in +2
  .nf
  # svccfg -s svc:/system/process-security setprop default/aslr = true
  .fi
  .in -2
  .sp
  .P
  This can be done by any user with the \fBsolaris.smf.value.process-security\fR
  authorization.
  .P
  Since security-flags are strictly inherited, this will not take effect until
  the system or zone is next booted.
--- 76,105 ----
  .RE
  
  System default security-flags are configured via properties on the
  \fBsvc:/system/process-security\fR service, which contains a boolean property
  per-flag in the \fBdefault\fR, \fBlower\fR and \fBupper\fR, property groups.
! The value indicates the setting of the flag, flags with no value take their
! defaults.  For example, to enable ASLR by default you would execute the
! following commands:
  .sp
  .in +2
  .nf
  # svccfg -s svc:/system/process-security setprop default/aslr = true
  .fi
  .in -2
  .sp
  .P
+ To restore the setting to the defaults you would execute:
+ .sp
+ .in +2
+ .nf
+ # svccfg -s svc:/system/process-security delpropvalue default/aslr true
+ .fi
+ .in -2
+ .sp
+ .P
  This can be done by any user with the \fBsolaris.smf.value.process-security\fR
  authorization.
  .P
  Since security-flags are strictly inherited, this will not take effect until
  the system or zone is next booted.