Add phpdoc to signal return type of Loader::db
Add phpdoc to signal return type of Loader::db

Adding the return type allows auto-completion systems
to automatically suggest methods and properties.

Former-commit-id: 2ae5c25244e025c8b3763f49b3974e3a6935124b
a3020/concrete5,mainio/concrete5,MrKarlDilkington/concrete5,acliss19xx/concrete5,a3020/concrete5,olsgreen/concrete5,concrete5/concrete5,mlocati/concrete5,biplobice/concrete5,hissy/concrete5,hissy/concrete5,KorvinSzanto/concrete5,biplobice/concrete5,jaromirdalecky/concrete5,concrete5/concrete5,deek87/concrete5,mainio/concrete5,biplobice/concrete5,jaromirdalecky/concrete5,deek87/concrete5,mlocati/concrete5,deek87/concrete5,olsgreen/concrete5,biplobice/concrete5,rikzuiderlicht/concrete5,triplei/concrete5-8,haeflimi/concrete5,haeflimi/concrete5,triplei/concrete5-8,mlocati/concrete5,concrete5/concrete5,jaromirdalecky/concrete5,triplei/concrete5-8,rikzuiderlicht/concrete5,mlocati/concrete5,mainio/concrete5,haeflimi/concrete5,olsgreen/concrete5,MrKarlDilkington/concrete5,MrKarlDilkington/concrete5,acliss19xx/concrete5,deek87/concrete5,hissy/concrete5,KorvinSzanto/concrete5,haeflimi/concrete5,concrete5/concrete5,hissy/concrete5,acliss19xx/concrete5,KorvinSzanto/concrete5,jaromirdalecky/concrete5,rikzuiderlicht/concrete5