Read /proc/qemupid/stat file to refresh process info,
include: parent pid, userspace time, task state and etc.
According to these data, add two display itemsi to vmtop:
S: task state
P: physical processor that task is runnning on
Signed-off-by: NJiajun Chen <1250062498@qq.com>

vmtop is a userspace tool which you can run it in host
to help detecting VM's performance.
1. Implement the basic display framework, realize loop display
   and field filter. Press 'f' to enter field filter mode and
   press 'q' to quit.
2. Build compiling project by autotools.
3. Add Mulan license for project.
Signed-off-by: NJiajun Chen <1250062498@qq.com>