syscalls/add_key{01,02}: Cleanup

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
configure, add_key{01,02}: Add check for linux/keyctl.h

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
containers: Update .gitignore files

The various check_for_* binaries are now gone.

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
containers/netns: Prefix files with netns.

Files with names as child.sh and similar are likely to clash with other
poorly named test files. This commit add netns_ prefix to all netns
files and updated scripts and runtest file accordingly.

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>