Task #3172
Updated by Junxiao Shi over 8 years ago
Complete Face refactoring as LinkService+Transport.
* Delete old `Face`.
* Rename `LpFace` as `Face`.
* Modify `Channel` and `Factory` subclasses to return `Face` directly without wrapping into `LpFaceWrapper`.
* Delete `LpFaceWrapper`.
* Modify forwarding and management to use new `Face` methods, signals, and counters.