r821 - New 2016/2017 Guild And Item Packets / Official Guild Master Change

[Rytech 392]

=General
*ZC_ITEM_PICKUP_ACK_V7
*ZC_GUILD_INFO3
*ZC_MEMBERMGR_INFO2
-Added support for these packets.
-Thanks goes to Lemongrass for figuring out the new structures.
-
-This enables new features on 2016-12-28 and newer clients.
-Previewing headgears and garments on character when viewed from
-items in carts and items picked up.
-Guild member listing now shows the last date each member was
-online. Currently the date won't show properly until I code
-in a system for saving a timestamp for guild members.

*Changing guild leaders is now possible through the guild window.
-If woE is active, the guild master is on a guild related map,
-or the targeted person to become the guild leader is not online,
-the change will fail.

*Updated the "changegm" command to fail if WoE is active.