Create rules to add/remove symlinks for bash completion.

Create rules to add/remove symlinks for bash completion.

By default, there is no out-of-the-box bash completion for lxc tools.
This is due to dynamic loading of completions, that requires the
completion filename to be the same as the command (e.g. `lxc-start`
expects a completion filename `lxc-start`). But all commands are in file
`lxc`, which is not read.

Signed-off-by: Edenis Freindorfer Azevedo <edenisfa@gmail.com>