Add sharetab to joyent zones

*** 57,66 ****
--- 57,67 ----
          <mount special="ctfs" directory="/system/contract" type="ctfs" />
          <mount special="mnttab" directory="/etc/mnttab" type="mntfs" />
          <mount special="objfs" directory="/system/object" type="objfs" />
          <mount special="lxproc" directory="/system/lxproc" type="lxproc" />
          <mount special="swap" directory="/etc/svc/volatile" type="tmpfs" />
+         <mount special="sharefs" directory="/etc/dfs/sharetab" type="sharefs" />
  
          <!-- Devices to create under /dev -->
          <device match="arp" />
          <device match="bpf" />
          <device match="conslog" />