lxc-alpine: do not drop setfcap Signed-off-by: Jakub Jirutka <jakub@jirutka.cz>

lxc-alpine: mount /dev/shm as tmpfs Signed-off-by: Jakub Jirutka <jakub@jirutka.cz>

lxc-alpine: mount tmpfs under /run When running under grsecurity kernel or userns, it can't be mounted from inside. Signed-off-by: Jakub Jirutka <jakub@jirutka.cz>

lxc-alpine: completely rewrite the template script New template script is more readable and robust, uses cache and external LXC config file as other templates. Signed-off-by: Jakub Jirutka <jakub@jirutka.cz>