dock:: docked app manager.

1. handle docked app(not finish).
2. fix xpm image is not shown on dock.
dock:: fix typo, dock/undock.

1. fix typo.
2. dock.
3. undock.
4. fix detachNormalApp panic.
Merge branch 'develop' of https://github.com/linuxdeepin/dde-daemon into develop