* Added item with GUID flag as `CHKADDITEM_NEW` in pc_checkadditem
* Adjust inventory blank check for guid item to `+n`
* Moved slot check as item_data function
* Removed quantity force-set-to-1 check for buying equip from cashshop, it will gives the item to player just like item with GUID flag
* Alphabetically sorted includes.
* Updated copyright and license text to match across all files.
* Removed pragma once define in header files in lieu of ifdef guards.
* Initial progression of moving the map-server to C++ format.
* Converted all core files to .cpp and header files to .hpp.
* Refactored the refine database parser to utilize native YAML C++.
Thanks to @Jeybla and @lighta for their help!
