[Quest API] Add inventory->CountItemEquippedByID(item_id) and invento…

…ry->HasItemEquippedByID(item_id) to Perl/Lua. (EQEmu#1963)

- Add $inventory->CountItemEquippedByID(item_id) to Perl.
- Add $inventory->HasItemEquippedByID(item_id) to Perl.
- Add inventory:CountItemEquippedByID(item_id) to Lua.
- Add inventory:HasItemEquippedByID(item_id) to Lua

Merge branch 'multithreaded-net' of github.com:EQEmu/Server into mult…

…ithreaded-net

Add file export to lua-api.md

Changes to UF and above clients on how spell buff tics are synced.

Changes to UF and above clients on how spell buff tics are synced.

Changes to UF and above clients on how spell buff tics are synced.

Fix lua events

Inventory V2 - Added ItemSlot Structures

Updated/activated EQDictionary code to use the new possessions enumer…

…ation

Merge branch 'master' of https://github.com/EQEmu/Server