add init.lxc.static binary

To avoid having to copy all the library dependencies into the container.

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>
execute: bind init.lxc.static into container

Changelog:

May 19: put init.lxc.static into container's root dir
	rather than under SBINDIR [stgraber].

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>
execute: try /lxc.init.static as last resort

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>
execute: don't bind mount init.lxc.static if lxc-init is in the container

Move choose_init into utils.c so we can re-use it.  Make it and on_path
accept an optional rootfs argument to prepend to the paths when checking
whether the file exists.

Also add lxc.init.static to .gitignore

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>
configure.ac: don't let -lcgmanager end up in LIBS

AC_SEARCH_LIBS always places the library being queried into LIBS.  We
don't want that - we were only checking whether a function is
available.  Not everything (notably not init.lxc.static) needs to
link against -lcgmanager.

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>
Fix building init.lxc.static under bionic

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