LU-12734 misc: add bash completion for lctl set/get_param

Add some start of bash completion for lctl, mainly set_param and
get_param, and modify build system to install it.

Test-Parameters: trivial
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Change-Id: I16d2698e782702375c7fa3edf3bfde2e3b197297
Reviewed-on: https://review.whamcloud.com/36105
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Quentin Bouget <quentin.bouget@cea.fr>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>