Proc list for bookkeeping of running processes

[Liblor]

Doubly linked list for bookkeeping of processes, as no kill is implemented yet, there is no remove from the list.

we have get_pid_array(struct processserver_state *ps, struct process_pid_array **ret_pid_array) to get a struct pid_array for replying to a rpc request

• [x] insert process
• [x] get pid_array of all processes
• [x] get name by pid