Merge pull request #7102 from Icinga/feature/boost-fs-7101

Replace self-written filesystem ops with boost.filesystem

diff --cc lib/base/scriptglobal.cpp
Simple merge

diff --cc lib/cli/apisetuputility.cpp
Simple merge

diff --cc lib/config/configcompilercontext.cpp
Simple merge

diff --cc lib/remote/configobjectutility.cpp
Simple merge