pc__client_force_join should test client->worker first
free uv_xxx_t in pc_client_destroy when no pc_client_connectX is called
Revert "free uv_xxx_t in pc_client_destroy when no pc_client_connectX is called"

This reverts commit 586ed8b13f8807b31cd1f25d116b788e3df5dcf3.
Merge pull request #25 from eminom/master

One problem in pc_client_destroy