unify libcgroup tools -h output

unify libcgroup tools -h output

unify libcgroup tools -h output

use <controllers>:<path> as a parameter of -g
        * cgclassify
        * cgget

fix typos
        * cgget
        * cgset

fix indentation
        * cgconfig
        * cgsnapshot

Signed-off-by: Ivana Hutarova Varekova <varekova@redhat.com>
Acked-by: Jan Safranek <jsafrane@redhat.com>
Acked-by: Dhaval Giani <dhaval.giani@gmail.com>