Fix header name in lxcmntent.h

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Add check for sys/timerfd.h

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Rename utmp.c/utmp.h to lxcutmp.c/lxcutmp.h

This avoids conflict with the system header utmp.h.

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Build lxcutmp.c without timerfd.h or utmpx.h

This adds a local implementation of the bits we need form timerfd.h and
utmpx.h so that the LXC utmp watch can be used with libc that don't implement
the same functions as eglibc.

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>