missing: define MS_REC and MS_SHARED if not defined already
efi: various cleanups
update TODO
manager: pass environment over daemon-reexec

Fixes this bug:
alxchk > systemctl --user set-environment A=B
alxchk > systemctl --user show-environment | grep ^A=
A=B
alxchk > systemctl --user daemon-reexec
alxchk > systemctl --user show-environment | grep ^A=
alxchk >
efi: add missing #include