libceph: cleanups preparing for state cleanup

I am working on some fairly big changes to the ceph/RADOS client messenger code. The ultimate goal is to simplify the code by having it more obviously follow a state machine, but getting to that point isn't necessarily easy.

My approach is to make evolutionary changes, making a long series of small changes, each of which either produces code that works identical to before, or which very explicitly fixes a bug or adds or modifies a feature while continuing to provide functionality that is equivalent and/or meets what is required.

This series contains a few small batches of changes to begin this process. In general they're dependent on each other, so they are being provided in one series, but I group them below into some smaller logical subsets.

-Alex

[PATCH 01/13] libceph: eliminate connection state "DEAD" [PATCH 02/13] libceph: kill bad_proto ceph connection op [PATCH 03/13] libceph: delete useless SOCK_CLOSED manipulations
These three delete dead/unused code

[PATCH 04/13] libceph: rename socket callbacks
[PATCH 05/13] libceph: rename kvec_reset and kvec_add functions
These two simply rename some symbols.

[PATCH 06/13] libceph: embed ceph messenger structure in ceph_client [PATCH 07/13] libceph: embed ceph connection structure in mon_client
These two each change a structure definition so that what was once a pointer to a structure becomes instead an embedded structure of the pointed-to type. Doing this makes it obvious that the relationship between the containing structure and the embedded one is purely one-to-one.

[PATCH 08/13] libceph: start separating connection flags from state
This identifies a set of values kept in the "state" field and records them instead in a new "flags" field, so it is obvious the role each plays (whether it's a state diagram state, or whether it's a Boolean flag).

[PATCH 09/13] libceph: start tracking connection socket state
This adds code to explicitly track the state of the socket used by a ceph connection. It begins the process of trying to clean up some fuzziness in how the overall state of a ceph connection is tracked.

[PATCH 10/13] libceph: provide osd number when creating osd [PATCH 11/13] libceph: init monitor connection when opening [PATCH 12/13] libceph: fully initialize connection in con_init() [PATCH 13/13] libceph: set CLOSED state bit in con_init
This series moves things around a bit so that all ceph connection initialization is done at one time, by code defined with the "net/ceph/messenger.c" source file. It also makes explicit that a newly initialized ceph connection is in CLOSED state.