Squashed 'external/devlib/' changes from bdb04aa8d..cd8720b90

cd8720b90 module/cgroups: Fix move_tasks()/move_all_tasks_to()
03569fb01 version: Bump minor version number
22f53f117 version: Bump revision number
e0abb9db4 collector/dmesg.py: Allow nesting DmesgCollector
c29d386e8 target: Allow relative path for for push/pull
adad59fdb target: Add Target.makedirs(as_root=False) parameter
48329b789 target: Add exception message when module fails to load
728b59ad7 utils/ssh.py: Make SshConnection._background() more robust
2b3854846 connection: Use -- in kill command

git-subtree-dir: external/devlib
git-subtree-split: cd8720b901bc6b3bbdd521396e23165d6c425023