Fix some marginal bugs, and the version of [AV]faces.

- Bump version of [AV]faces to 2.2.
- With very bad luck, some channel numbers could overflow the range of an integer due to float rounding, and produce DEBUG_CHANNEL or PUBLIC_CHANNEL as output.
- If both CHANGED_INVENTORY and CHANGED_LINK came at the same time, [AV]prop would fail to handle both.
- There was code that did nothing in [AV]faces. While it caused no bug per se, if it was reused in future then it could be affected by the same problem as that in [AV]prop.

AVsitter2/[AV]root-security.lsl

@@ -109,7 +109,7 @@ main_menu()
 dialog(string text, list menu_items)
 {
     llListenRemove(menu_handle);
-    menu_handle = llListen(menu_channel = ((integer)llFrand(2147483646) + 1) * -1, "", llGetOwner(), "");
+    menu_handle = llListen(menu_channel = ((integer)llFrand(0x7FFFFF80) + 1) * -1, "", llGetOwner(), ""); // 7FFFFF80 = max float < 2^31
     llDialog(llGetOwner(), product + "\n\n" + text, order_buttons(menu_items), menu_channel);
     llSetTimerEvent(600);
 }