This commit cleans up the includes for all the small tools across
the tree.
A few cases of returning EXIT_SUCCESS are replaced with returning
0 to avoid including <stdlib.h>.
Split out of #37344.
Let's move some logic from _DEFINE_MAIN_FUNCTION() and other places
in main-func.h into functions that we implement in main-func.c to
allow moving some included headers from the header to the .c file.
Now that the necessary functions from log.h have been moved to macro.h,
we can stop including log.h in macro.h. This requires modifying source
files all over the tree to include log.h instead.
We'll add another type of handler callback in the next commit, hence
rename the existing handler to be more precise what it is about:
handling hangups (either inline via tty, or explicit via user request)
We want systemd-pty-forward to be something that can be dropped in
somewhere without too much thought. To enable this, let's make sure
we forward various signals to the forked process. This makes sure that
any signals are delivered to the actual child process regardless of whether
it's running within systemd-pty-forward or not.
Jelle van der Waa
Daan De Meyer
Lennart Poettering
Yu Watanabe