Issue description:In User’s roster,contact’s subscription states is “from”,in contact’s roster,user’s subscription states is “to”,then if user send unsubscribe presence packet to contact,you will find contact receieve roster packet setting subscription state to “none”,I think this is a bug,conflict with RFC 3921:
Table 4: Recommended handling of inbound “unsubscribe” stanzas
±-----------------------------------------------------------------+
| EXISTING STATE | DELIVER? | NEW STATE |
±-----------------------------------------------------------------+
| “None” | no | no state change |
| “None + Pending Out” | no | no state change |
| “None + Pending In” | yes * | “None” |
| “None + Pending Out/In” | yes * | “None + Pending Out” |
** | “To” | no | no state change |**
| “To + Pending In” | yes * | “To” |
| “From” | yes * | “None” |
| “From + Pending Out” | yes * | "None + Pending Out |
| “Both” | yes * | “To” |
±-----------------------------------------------------------------+
Best Rgds
L.J.W