ADDED: Expand/Collapse All (but init) and Expand/Collapse All Childs

[giuseppe-dandrea]

Hi everyone, I added two functions:

• - Expand/Collapse all childs (only the first level) of the selected process
• = Expand/Collapse all processes (not init). It expands all processes if the selected process is collapsed and vice versa. (If the selected process is init, it consider the second process in the list because init is always expanded).

Used these two keystroke to test it quickly and I don't added any help for these keystroke in the program. If this PR is useful and could be merged, I'll improve it. Thanks.