define listtasksrecursive

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
make gettasksrecursive return ordered list

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
make gettasksrecursive recursive

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
remove duplicates from pids array

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
make pid search binary

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
add testcase for gettasksrecursive

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>