man: fix path in crypttab(5)

https://bugs.freedesktop.org/show_bug.cgi?id=75816
fstab-generator: simplify add_root_mount
coredump: retrieve comm information from /proc

Kernel mangles comm information in an irreversible way when comm
constains repeated spaces. Retrieve comm information from /proc, and
only fallback to the information provided on the commandline when
retrieving information from /proc fails.

Add exe information to the list of saved xattr.

https://bugs.freedesktop.org/show_bug.cgi?id=62043
coredump: log coredump even if core dumping fails

Journal might be functional even if we cannot write to
/var/lib/systemd/coredump.
Revert "Add systemd-coredumpctl as an alias for coredumpctl"

This reverts the documentation part of commit
dfdd0e0730385eef08f019863fd41168b05b6ab0.