xpc → sll Relation

File in src/util/xpc	Includes file in src/util/sll
downloadhelpers.cpp	either.h
downloadhelpers.cpp	visitor.h
downloadhelpers.h	eitherfwd.h
passutils.cpp	eithercont.h
passutils.cpp	slotclosure.h
stddatafiltermenucreator.cpp	slotclosure.h