Add API to define custom model relationships
Add API to define custom model relationships

Onyx47/core,flarum/core,billmn/core,Albert221/core,renyuneyun/core,flarum/core,Luceos/core,zaksoup/core,Albert221/core,renyuneyun/core,Luceos/core,kirkbushell/core,Albert221/core,billmn/core,falconchen/core,Albert221/core,vuthaihoc/core,dungphanxuan/core,falconchen/core,kirkbushell/core,Luceos/core,kirkbushell/core,utkarshx/core,malayladu/core,datitisev/core,Luceos/core,dungphanxuan/core,liukaijv/core,malayladu/core,flarum/core,datitisev/core,huytd/core,Onyx47/core,Onyx47/core,dungphanxuan/core,billmn/core,vuthaihoc/core,utkarshx/core,zaksoup/core,datitisev/core,kidaa/core,zaksoup/core,renyuneyun/core,kirkbushell/core,falconchen/core,liukaijv/core,kidaa/core,renyuneyun/core,vuthaihoc/core,jubianchi/core,malayladu/core,huytd/core,kidaa/core,malayladu/core,datitisev/core,jubianchi/core